


Impostors on the Garreg Mach Enterprise

by JajaLala



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Alternate Universe - Among Us (Video Game) Setting, Alternate Universe - Space, But will frequently switch POVs bc all the students deserve quality time, Canonical Character Death, Gen, Kissing, M/M, Marianne von Edmund/Support, Minor Character Death, Murder, Murder Mystery, Non-graphic Murder, Nonbinary My Unit | Byleth, Other Additional Tags to Be Added, POV Alternating, POV My Unit | Byleth, Stabbing
Language: English
Status: Completed
Published: 2020-12-07
Updated: 2021-01-02
Packaged: 2021-03-09 18:01:35
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 9
Words: 19,832
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27930436
Author URL: https://archiveofourown.org/users/JajaLala/pseuds/JajaLala
Summary: Byleth and Jeralt get a distress beacon from a large spaceship, the Garreg Mach Enterprise. Upon docking, they learn that there's been a murder and are persuaded to help catch the murderer.As the murder count rises each day and people are forced to face each other in different ways, loyalties are tested and it becomes clear catching the impostor(s) may be the only way anyone gets off this ship alive.[The Among Us X Fire Emblem: Three Houses fic my brain wouldn't let go of. Updates twice a week]
Relationships: Dorothea Arnault & Manuela Casagranda, Edelgard von Hresvelg & Hubert von Vestra, Edelgard von Hresvelg & Jeritza von Hrym, Felix Hugo Fraldarius/Sylvain Jose Gautier, Ferdinand Von Aegir & Manuela Casagranda, Jeritza von Hrym & Hubert von Vestra, Other Relationship Tags to Be Added, Raphael Kirsten & Ignatz Victor
Comments: 2
Kudos: 15





	1. The Distress Beacon

**Author's Note:**

> Although I'm using Byleth as the central detective-type character, I really love all the characters of FE3H so there will be a lot of vignettes in different students' POVs. Not in this first chapter, though, since I'm establishing stuff first.
> 
> I will be killing people off (bc Impostors gotta murder), but know beforehand I have delicate sensibilities and hate being sad, so I'm not gonna be very graphic about the murders. I chose not to use archive warnings because with a cast as large as Fire Emblem it's hard to say what constitutes a "major" character, but if you are upset with the idea of any of the characters being killed (though it is not described in great detail or ruminated upon) this fic may not be for you. Aside from possibly major character death (depending on how broadly you define "major character") none of the other archive warnings apply.

“There’s a distress signal,” Byleth commented, staring at the notification on the control panel.

Jeralt, who had been leaning back in his co-pilot seat, almost asleep, sat up straight at the alert. “From what?”

“A large ship,” Byleth told him, analyzing the signal, “Probably four, maybe even five-tier.”

Jeralt snorted. “How do they think a two-person buggie like ours can help them?”

Privately, Byleth thought the ship must have no choice. They were in dead space; the few planets  and systems they passed were uninhabited, and the most exciting parts of their journey were asteroid fields. It had been at least nine circadian cycles since Byleth and Jeralt had left the trading post they had stopped for supplies, and it would probably be nine or more before they reached the next trading post. Ships tried not to travel through dead space like this often, not unless they were well-equipped and prepared for emergencies they could solve in isolation. Jeralt and Byleth were perhaps unique in that they could stand to spend days  together  in almost silence without going mad, and were willing to risk the dangers to get places faster.

There was a beeping sound. “They want to open communications with us.”

Jeralt stared at the control panel for a moment, before letting out a large sigh. “Alright, we’ll just tell them we don’t have any resources to spare.”

With his permission, Byleth accepted the comm.

“ _H-zzz,-”_ The caller appeared on the main screen, fuzzing a bit before stabilizing, though the image was pixelated Byleth could identify the speaker had green hair. _“Hello? This is Garreg Mach Enterprise, do you copy?”_

Jeralt leaned forward  to take over . Byleth was relieved, they weren’t usually all that great with speaking, and could not think of a polite way to reject them. Jeralt’s voice was gruff as he spoke into the comm, “We’re a small ship, we only have enough supplies for ourselves. We can help relay a message elsewhere, but we won’t be able to help you.”

“ _We don’t need resources,”_ The caller clarified, _“We’re doing quite well on that front.”_

Jeralt frowned. “Then why the distress signal?”

“ _There’s been a… a situation on our ship, and we don’t know who to trust. We’ve agreed that if we could find someone uninvolved, we could trust them as a neutral party to help us… mediate.”_

The vague phrasing had Jeralt’s brow furrowing, and he glanced at Byleth. Byleth gave a shrug. He eventually responded. “Alright, we’re not in a rush, we can stop in for a bit to help. Can we dock?”

“ _Thank you! Yes, let us open our port...”_

  
  


* * *

  
  


“A murder?”

“Yes, a murder,” Seteth, the man who had called them, repeated.

Jeralt ran a hand over his face as he groaned. “I shouldn’t have answered that distress call.”

Alois slapped him on the back, “But then we wouldn’t have been able to reconnect! Isn’t it crazy that it was  _ your _ ship closest to ours in the vast expanse of space? One might even call it fate!”

“You’re awfully chipper for someone whose coworker just got murdered.”

Alois shrugged. “Of course it’s terrible what happened to Anna, but in all honesty I didn’t know her too well. She was quite friendly, but kept to herself most the time,” He leaned towards Byleth, “Kind of like this  sprout here, who’s this?”

“…My kid.”

Alois tilted his head. “Like… like your child?” He focused on Byleth again, “Is he actually your father?”

Byleth shrugged. “Probably.”

He laughed, large and booming. “What a riot! Jeralt, their sense of humor is just like yours.”

That wasn’t intended to be a joke, but Byleth didn’t think it would help to clarify. They had known Jeralt as long as they could remember, and if Jeralt said they were parent and child, Byleth thought it was more likely to be true than not.

Seteth grumbled, “Can we get back to the murder situation?”

“Of course,” Jeralt acquiesced, “Me and my child will do our best to figure out what’s going on.”

“Then perhaps it would be good if you got to know some of the crew and occupants of this vessel. There are about fifty people on board, though a majority are split between three houses.”

“Houses?”

“Not literal houses, of course, but we’ve split people into living groups, and people tend to live and eat in their groups. Each group has a leader who is supposed to keep track of the occupants. A few administrative people such as myself and my little sister are outside that system, though.”

Byleth glanced around. A little sister?

Jeralt nodded. “I suppose we ought to start with talking to each house leader.”

  
  


* * *

  
  


Edelgard sat straight, shoulders relaxed, as she responded to their inquiries, listing all of the Black Eagle House members and summarizing their alibis for the incident.

“…And Monica says she was emptying the garbage chute, though there wasn’t anyone around at the time to confirm that. Not having an alibi is hardly damning, though, when most people don’t have an airtight one. For example, Bernadetta is almost always in her room, which means no one sees her, but she must have left at some point during the day of the murder because she did the gardening she was assigned by the end of the day...”

There was also the imposing figure beside Edelgard, Hubert Vestra. Byleth couldn’t put their finger on it, but there was something shady about him. He was quiet during most of the questions, but when he had a chance to speak he insisted that he and Edelgard had been together for hours before the body was discovered.

Soon after Edelgard described Caspar, the blue-haired boy himself entered the room. “I heard the detectives are here?”

“We’re not _really_ detectives,” Byleth clarified.

A tall boy with green hair (Linhardt?) hurried into the room as well, “Caspar, I told you to slow down-”

“I wanna help!” Caspar exclaimed, “I’m ready to catch the murderer, just tell me who it is and I’ll grab ‘em!”

Linhardt sighed, shaking his head. “I told you, Caspar, they’re being allowed to investigate because they’re strangers, you don’t have an alibi, so having you investigate is kind of…”

“I _swear_ I didn’t do it, though!” Caspar told him, “If anything, the fact that the ship didn’t hit _any_ asteroids thanks to my careful aim all afternoon should be alibi enough!”

“Still, you’re a suspect, so you shouldn’t…”

“Actually,” Jeralt cut in, “It wouldn’t hurt to have a little help from folks.”

Byleth glanced sideways at him.

Linhardt blinked. “…Really?”

He nodded. “After all, Byleth and I may not be suspects, but we also don’t really know anyone or anything about this ship. If you guys have information that could help us figure things out…”

Caspar grinned. “I’ll do my best! I’ll go look around for clues!”

He ran out of the room, energized by Jeralt’s permission.

Linhardt also seemed to be considering the permission, muttering to himself as he walked away.

Edelgard spoke, “Apologies, Caspar can be rather excitable.”

“That’s alright,” Jeralt assured her, “It’s good to have more people helping.”

Hubert commented, “I think a murderer would love to help out to throw investigators off their trail.”

Byleth frowned slightly at his implication. “Are you saying we should suspect Caspar?”

He chuckled. “I’m just saying if you trust everyone who says they want to help, the murderer will have much easier job escaping your notice.”

* * *

  
  


The second house they met had a leader called Dmitri, who sat stiffly at a table.

“Many of us are quite close,” Dmitri spoke quietly, “To be honest, I find it hard to believe that anyone in my house would commit a murder.”

“Close?” Jeralt asked.

The large man standing beside Dmitri who had yet to say a word, nodded.

Dmitri explained, “Many of us came from a planet that was… warring with another nearby. In the course of some battles, Ingrid lost her fiance, Felix lost his brother, I lost my family, and Dedue…” He glanced at the man beside him, who remained expressionless, “He lost his whole planet.”

Though the conversation moved on from there, Jeralt and Byleth were in a somber mood while leaving the Blue Lion’s quarters.

However, as they were in the hallways, rapid footsteps came up behind them.

They turned to see a lean man with black hair pulled back. That sounded like the description Dmitri gave of Felix. “You guys are the investigators, right?”

“Yes,” Byleth confirmed.

His expression was serious. “I have to tell you about Dmitri. He’s not who you think he is.”

Jeralt and Byleth straightened up and took a step closer to Felix to hear the details.

“He probably told you that sob story about our home planet, right?”

“Yes?”

“Well he always leaves out his part in the tragedy. When he was in battle… He wasn’t just a killer, he was a _beast,_ some sort of monster that seemed to enjoy killing. If there’s anyone on this ship who might kill just to get it out of his system, it’s that boar.”

Jeralt glanced at Byleth, a little alarmed at the intensity of Felix’s accusation.

Felix apparently noticed their wordless exchange. “I know I don’t have evidence, but I thought you ought to know that the meek little persona he takes on is covering something much more severe.”

With that, Felix spun on his heel and left, returning to the Blue Lions house.

  
  


* * *

  
  


Third was the Golden Deer house, where Claude welcomed them before taking a seat and getting comfortable, resting one leg on the table.

He seemed fond of all of the Golden Deer occupants, though he sometimes was critical in his descriptions of them, it seemed the realm of teasing rather than sincere complaint. He also seemed determined to paint each of them as if they couldn’t be guilty.

“Ignatz is much too timid to kill someone, and Lorenz would _never_ risk getting his hands dirty.” He glanced at the girl in pigtails who sat on the table. “And Hilda here is _much_ too lazy to commit a whole murder.”

“Hey!” She pouted, “If I really wanted to, I’m sure I could muster up a _little_ effort.”

“And why would you kill Anna?” He teased, “Jealous there was someone else with pink hair on this ship?”

Hilda laughed. “If that were my problem, I would have sneaked bleach into her shampoo. Death  _ is _ a lot more effort.”

Jeralt refocused them. “Rather than your personalities, we’re more interested in who has alibis.”

As Claude explained the information he knew, Byleth noted someone peeking into the room through a cracked door. She had a gloomy face, with eyes that looked like they were haunted with the weight of her sins. The blue hair helped her identify her as Marianne, one of the Golden Deer.

Their eyes met, and Marianne’s widened a fraction before she turned and fled, quiet as a mouse.

“…And Lysithea was reading in the library, you can ask Tomas about it, as the ship librarian he probably would have seen her.”

Jeralt nodded. “Will do. Is that everyone?”

“Everyone under my jurisdiction.”

“We’ll be heading out th-”

“Jeralt!”

Someone with short, ginger hair bounced into the room. Jeralt took a step back at her enthusiasm, but she was not dampened by the confused reception.

“I’m your _biggest_ fan,” She exclaimed, “I don’t know if you remember, but you spent some time at the Sauin trading post in the Leicester system? You came with such incredible stories about the universe, you inspired me!”

“Oh,” Jeralt had a small smile, “I’m, uh, glad to hear it.”

“When you get a chance, I’d _love_ to hear more about what you’ve been up to.”

Claude laughed. “Come on, Leonie, let’s give the man and his kid some space.”

“Kid?” Leonie finally seemed to notice Byleth. “…Hm.”

“We should get going, right Byleth?”

Byleth nodded.

  
  


* * *

  
  


They met a few more people, including some others not directly affiliated with the houses. By the end, however, there was not obvious answer to who the murderer was.

Seteth set them up to rest in Anna’s old residence, a small pod, but large enough to stuff a second bed and let them both sleep for the night.

Though Byleth and Jeralt were never ones for long conversations, they did speak their thoughts out loud that night. Running over all the information they knew and everyone they had met.

Unfortunately, there wasn’t anyone obvious. There were too many people without an alibi to use that as evidence, and basically no one had a close relationship with Anna.

They decided to have another go at the investigation tomorrow. They had mostly spoken to the house leaders, not every individual. Perhaps if they asked everyone they would be able to get more information. They agreed to split up and talk to as many people as possible tomorrow.


	2. Anna

**Summary for the Chapter:**

> Ignatz and Raphael bond, Manuela has simps, Marianne is cursed, and Jeralt...?

Ignatz groaned as he worked. As much as he enjoyed working in electrical, fixing the wires that had disconnected by linking up the correct colors, it was the kind of task that was not mentally taxing. Which meant he could drown in his own thoughts.

There was a murderer on Garreg Mach Enterprise. They were a long ways away from any sort of civilization that might have actual detectives. Nobody wanted to be the next victim if this turned out to be a serial killer. Ignatz knew what was coming next.

This wasn’t the first time Ignatz ended up stranded on a ship in dead space with a killer onboard.

“Please no one else die,” He muttered, _“Please_ no one else die, I don’t think I can handle the stress…”

He squinted at the wires. It was getting a little hard to see the colors, had it gotten darker in here? He took a step back and realized it wasn’t the room that was getting darker, but rather a large shadow behind him. His heart rate spiked.

Something touched his back, and he jumped up, letting out an undignified squeak of fear.

“Hey, hey buddy, what’s got you so on edge?” A familiar voice cajoled, “It’s just me, your friend Raphael!”

Ignatz heart did calm at the knowledge of who exactly was sneaking behind him, but he was still uneasy. “…Oh.”

Raphael smiled, warm despite everything. “What are you up to, wires?”

“Y-yes,” Ignatz closed the panel, despite not being done, “I have to go.”

“Wait,” Raphael grabbed his arm, preventing him from fleeing as he intended, “Are you alright? It seems like you’ve been avoiding me.”

Ignatz wanted to run away, but Raphael had his arm… and didn’t Raphael deserve Ignatz’s apology at least? “I… I didn’t want to bring up more bad memories for you.”

Raphael seemed legitimately confused. “Bad memories? Bro, I have only good memories with you.”

“Then what about what happened on… on the Leceister merchant ship we were on as children?”

That finally weaseled a frown out of Raphael. “Of course I remember that, but why are you bringing it up?”

“Isn’t it painful to be with me, especially with the same thing happening again…”

“Hey, hey now,” Raphael laughed while pulling Ignatz closer, “You’re making a lot of jumps here. We haven’t even held a vote on this ship, and it would never be painful to be with you.”

“But it’s my parents’ faults that yours…” Ignatz gulped, scared to admit exactly what happened, “I’m sorry.”

“That’s not your fault, or… or even fully your parents’,” Raphael’s smile faltered a bit as he clarified, “I mean, they were just going along with the flow. There was some strong testimony against my old folks, almost _everyone_ voted for them.”

“But how can you be so nice to me when it’s my parents who made you into an orphan?”

Raphael pulled him into a hug. “We were  _ kids, _ Ignatz, neither of us got a vote. I don’t hate you for what your parents did.”

Ignatz teared up a bit, not feeling absolved but selfishly enjoying Raphael’s excuses. “I just don’t want the same thing to happen here.”

“It’ll be okay,” Raphael reassured him, “We just gotta stay calm and stick together, yeah? Don’t go running off alone. I can’t think of anything riskier in times like this.”

Ignatz sniffled. Raphael  _ did _ have a point, neither of them would even be able to worry about being voted off if they got murdered first. “…Alright.”

* * *

  
  


Dorothea sat on the patient’s table.

“Only patients are supposed to sit there, you know,” Manuela chastised her, though her tone was not stern.

Dorothea grinned, crossing her legs and leaning forward despite Manuela not even looking at her. “Oh but it’s so comfy here!”

Manuela groaned, still focusing on something on her desk instead of Dorothea. The lights in the medbay were dim, which told her that Manuela was almost definitely hungover. However, that normally meant  _ Manuela _ would be sprawled on the patient’s table, taking a midday nap or, in more severe cases, hooking herself up to an IV to hydrate herself.

Instead, though, Manuela was hunched over her desk, barely paying  _ any _ attention to Dorothea. “What have you got there that’s so interesting?” Dorothea asked.

“Some liquid that was on the dagger used to… You know.” Manuela sighed, rubbing her neck. “Those mysterious guests of ours asked me to take a look, since I _am_ supposed to be the ship doctor.”

“And you actually took on the work?”

“Despite my behavior, I’m technically supposed to be working on this ship,” Manuela told her with slight seriousness, “It doesn’t hurt that the big one, Jeralt, is a breath of fresh air from seeing the same old faces every day on this ship.”

Dorothea pouted. “Are you interested in him?”

Manuela gave a good-natured huff. “Normally I don’t go for men with kids, but it’s not like I’m getting any younger…”

“You could have anyone you want!” Dorothea exclaimed, not willing to stand for _anyone_ critiquing her idol, even if it was Manuela herself, “You’re as beautiful today as you were ten years ago!”

Perhaps she had changed  _ slightly, _ but overall Manuela still carried herself regally, and a change in the  _ kind  _ of beauty she radiated did not mean a reduction in that  inherent beauty. Dorothea still had stars in her eyes, same as she did when she first saw Manuela on Holoshows as a child. Those performances she saw had encouraged Dorothea to learn performance herself, in the hopes that she might get a little closer to Manuela. Once Manuela retired, however, it turned out volunteering on the Garreg Mach Enterprise was a much faster way to get close to her idol.

Manuela laughed. “Now, now, Dorothea, you’ll make me blush.”

Before Dorothea could insist, the door to the Medbay flew open and the last person she wanted to see stepped in.

Ferdinand, hair freshly brushed, stumbled to Manuela’s desk as he bemoaned, “Manuela, I am in need of assistance, I have the most terrible headache!”

His theatrics made Manuela look up properly, and Dorothea felt a stab of jealousy at the misdirected attention. She had been trying to be at least a  _ little _ considerate of Manuela’s work, but Ferdinand gets to burst in without any reprimand-

“Ferdinand, this may shock you, but I have some actual work to do today. Whatever poison was used on this dagger is definitely not an easy to analyze one. I know this is just an excuse to see me, just like the last three days you’ve been here. Take a band-aid or a painkiller if I’m wrong.”

Dorothea smirked. Manuela’s scoldings were rare, but deserved.

Ferdinand was persistent, though. “Then why is Dorothea in here?”

“Dorothea is-” Manuela paused, thinking, before she continued, “…I suppose you’re right, you both should leave and let me concentrate.”

With a pout, Dorothea hopped off the table and strutted, grabbing Ferdinand and pulling him out as well. “If you insist, Manuela, we would never want to cause you distress!”

Ferdinand sputtered a bit at being manhandled, but once the medbay door closed behind them she let go of him.

“Great job,” Dorothea scolded him, “Now _neither_ of us get to hang out with her.”

“I barely got to see her! If anyone should be mad, it’s me!”

“You see her _every_ day,” Dorothea did her best impression: “’I am Ferdinand Von Aegir, and I have _another_ paper-cut! Manuela, allow me to spend an hour going on about your radiance for just one band-aid!’”

Ferdinand’s lower lip jutted out at the accusation. “Well I’m not the only sunflower turning to bask in her sunshine.”

Dorothea groaned at his poetry. “Do you have to phrase it like that? You can just say it clearly: We’re  _ simps,  _ Ferdinand.”

He frowned. “I prefer to call myself an admirer.”

She spun around, arms crossed. “I think one simp is enough for her, you really should lay off.”

“You’re just saying that because you want her to yourself.”

“And you don’t?”

Rather than answering, Ferdinand changed the topic. “Then shall we have a truce while she’s working?”

Dorothea tapped her foot. As much as she disliked the idea of staying away from Manuela long, she supposed a true simp would be considerate of the fact that Manuela had some actual work to do for once. “Fine.”

  
  


* * *

  
  


Marianne wrapped her blanket around herself. She had been in her pod most of the day, wallowing in guilt. If she weren’t on this ship, would Anna have survived? Marianne knew she was cursed. She was much too bold trying to get close to people on this ship, and hadn’t she purchased a handkerchief from Anna the day before the murder?

It was obvious, Marianne caused Anna’s demise. If she weren’t here…

There was a knock on the door. “Marianne?”

It was Hilda’s voice. Marianne decided to stay quiet, Hilda would tire eventually.

“Marianne? Are you sleeping or something? I haven’t seen you all day.”

She wrapped the blanket tighter around herself. She couldn’t respond.

“…Well, I’ll try again later. If you don’t come out for dinner I’ll bring it to your room.”

Marianne almost choked on the sincerity. She didn’t deserve it. She would only bring ruin to this ship, and Hilda was one of the last people she wanted to destroy.

It was better that she was alone. She was a curse.

  
  


* * *

  
  


Byleth stared.

That was Jeralt’s body.

Their father. On the ground in electrical, knife through the back.

They were unable to move for a moment, completely stunned by the discovery. Then they sprung into action, turning him over to see if he had breath. Unfortunately, the blood was already turning brown on the ground, suggesting he had been dead for awhile.

When they determined he had no breath, no heartbeat, and was already turning stiff, Byleth let the tears fall.

**Notes for the Chapter:**

> *adds 'canonical death' to the tags*
> 
> Severe lack of Ignatz and Raphael content in this fandom, they're good boys.
> 
> I'm also amused by Dorothea and Ferdinand's similarities in taste/admirations


	3. Jeralt

**Summary for the Chapter:**

> The crew has a conference to establish alibis, new rules are put in place, and Monica wants to spend some time alone with Sylvain...

“I need to know where everyone was today and what they were doing,” Byleth told the room.

The whole crew was gathered in one large conference room, gathered around a series of tables. Most looked supremely uncomfortable with the news that Jeralt had been murdered, and a few had privately offered their condolences earlier. Leonie and Alois still had red eyes from crying at the news.

Unfortunately, emotions were not among Byleth’s talents, so they did not know how to respond to those feelings, much less their own. A life of traveling as a space mercenary meant that Byleth was much more comfortable with a task such as finishing Jeralt’s work: Finding the murderer on this ship.

“Let’s start from the left side of the room and go around.”

In preparation, Byleth had pulled out a journal Jeralt had gifted them. They had never really used it, journaling was more of Jeralt’s thing. Byleth had seen him scribbling in a small bound book most nights, detailing the events of the day. Byleth had suggested moving to a tablet before, but Jeralt insisted that analog tech was safer from distant hackers or glitches.

Now, with Jeralt gone, it seemed only appropriate that Byleth finally find a use for the empty journal they had: To take notes about any possible clues to the murder.

Hubert spoke first, “Edelgard and I spent 0700 to 0800 refueling the tanks before breakfast. We then had breakfast until approximately 0900, when we went on rounds to make sure everyone in the Black Eagles was accounted for. After that…”

  
  


* * *

  
  


Although some people like Hubert and Edelgard had companions who could vouch for them, most did not. Byleth was already starting to get a headache at the realization that too many people were lacking an alibi.

“…And um… I guess I was alone in the greenhouse for awhile. I did see Mercedes at dinner, though! She came to check on me when she saw smoke, so she can confirm I was far away from electrical around, uh… 1800? Mercie and I ate dinner together after that… and then we hear d the news,” Anette trailed off and glanced to the side, cuing the next person to go.

Ignatz bit his lip. “Er, I guess I should start, then? Uh, I was in electrical-”

Everyone around stiffened at the mention of the scene of the crime.

Ignatz squeaked. “Only in the morning, though! Raphael came in and we… talked for a bit. After that, I left with Raphael. Probably around 1130 or so?”

Byleth took a mental note that meant the murder must have happened after 1130. Then Byleth remembered the journal they had, and deliberately wrote down the detail.

  
  


* * *

  
  


“…So I was priming the shields from uh… around 1300 until 1600 or so,” Sylvain explained.

Felix beside him raised an eyebrow. “That’s an awfully long time to be working on shields.”

“That’s, uh…” Sylvain glanced around.

Monica, beside him, piped up, “That’s cause I was there and we got…” She bit her lip. “…Distracted.”

Felix gagged. “Nevermind, forget I asked.”

Byleth also didn’t want to hear the details of that. Dmitri had described Sylvain as a flirt, but it was still a surprise to hear people could be horny mere days after a murder was committed on their ship.

  
  


* * *

  
  


Sylvain breathed a sigh of relief with Monica’s corroborating testimony. He didn’t know how she realized he needed help, but he was thankful all the same.

He glanced across the room at the woman he was actually with earlier. Although he had fun earlier, he noticed at the conference that there was a man with his arm around her, and a ring on her finger he was certain wasn’t there several hours ago. She was resolutely avoiding his eyes.

Rather than start drama, he grinned at his luck with Monica stepping in to help him.

By the end of the meeting, there were no obvious clues as to who the murderer might be.

Byleth seemed to agree. “I can’t in good conscience accuse someone or put up a vote as to who it might be. There are simply too many people without alibis.”

Although Sylvain didn’t want to be voted off, he also was a little concerned with the fact that there was still a murderer on board, and nothing anyone could do about it.

“However, I think we should operate with new guidelines. Whenever possible, travel with _at least_ two other companions. Even if it means it takes a little longer for everyone to do their tasks, it’s better to stay safe and avoid being murdered. Not to mention it will give more people alibi corroborations.”

With that command, the crew was dismissed and people began returning to their pods or, if they procrastinated like Sylvain, their last task of the day.

Monica stuck to his side, grabbing his arm. “Let’s stick together, yeah? I’m a little scared,” She admitted with wide eyes.

Sylvain laughed. Monica was cute but… “Don’t worry, you’ll be safe with me.”

Though there were crowds as they dispersed and Sylvain made his way to the admin room, there was soon only a handful of people in the hallways they passed, gathered into tight trios.

Quietly, Sylvain thanked her, “Thanks for jumping in back there.”

“No problem,” Monica responded with a grin before whispering in his ear, “Though if you want to thank me, maybe we could make that fabricated alibi a reality?”

Sylvain took a moment to process the implication, before he went into damage-control mode. As cute as Monica was, there was something about her that didn’t sit right with him. He normally wasn’t too picky about who he was with but…

Somehow, he just couldn’t make himself attracted to redheads.

Sometimes he could stomach a gentle ginger if he pushed himself, but a dark red like Monica? He knew there was no good sense or logic to hair color, it’s not like redheads were evil. Sylvain  _himself_ was a redhead, so why couldn’t he stand it in his women? Perhaps he disliked people who were similar to himself.

Either way, despite Monica’s advances, he wasn’t interested. He cursed at himself inwardly, how was he idiotic enough to expect a girl to just help him out without expecting anything in return? “Ahaha,” He laughed gently, stalling for time as he tried to think of the kindest excuse to not hook up with her, “I don’t know, I do still have to swipe my card…”

“In admin?” Monica licked her lips. “This time of night, I bet there will be no one there at all.” She put a hand on his chest, looking at his body. “Probably no one would check in there until tomorrow morning.”

He gulped. She was coming on  _real_ strong, a rejection would be insulting, but he didn’t… 

“Sylvain!” Felix’s voice rang out down the hall.

Monica frowned at the interruption, but Sylvain found himself sighing in relief.

Felix sprinted over, but wasn’t even out of breath when he caught up to them. “Didn’t you hear Byleth? Groups of _three,_ not two.”

Sylvain laughed. “You caught me, Felix. I guess we ought to all three travel together.”

Unfortunately Monica was less enthused about the new safety buddy. “Sylvain wouldn’t kill me,” She said with a pout, “I trust him. You can go, we want to do some  _private_ things, right Sylvain?”

Sylvain floundered. “Uh…”

Felix grabbed Sylvain by his collar and pulled him out of Monica’s possessive grip. Sylvain did not resist at all, and his  unusually  easy compliance  made Felix furrow his brow. However, it did not stop Felix from chastising him, “You can’t even keep it in your pants for  _one day_ to follow the anti-murder precautions?”

Sylvain gulped, giving Felix a desperate expression as Monica grabbed the  _back_ of his shirt collar and pulled him back. “Can’t you take a hint?” She told Felix, pushing Sylvain behind herself as though she was protecting him, “Two people is already safe enough, if any murderer comes through Sylvain can fight them off. Besides, most people are going to sleep, the murderer probably is too.”

That seemed to discourage Felix, who seemed exasperated enough to give up on the situation.

Nope, Sylvain didn’t want that.

Felix gave one final look towards Sylvain, and since Monica was facing Felix with him behind her, Sylvain took the opportunity to mouth  _Help._

Felix’s eyes widened.

“…Two people are safe enough?” Felix repeated Monica’s words.

She nodded. “I’m just going to help him swipe his card in admin, and after that…” She smiled, “Who knows?”

“Do you have any tasks?” Felix asked.

Monica shook her head. “Did them all today. So I can spend all night with-”

Felix stepped forward, passing her and grabbing Sylvain’s arm. “Go to bed. I’ll go with him to swipe.”

She stomped her foot. “Don’t be obtuse! I thought I made it  _pretty_ obvious that we’re trying to hook up! Sylvain, you’re not going to let him get between us, are you?”

“Uh…” Sylvain had a stiff smile on, not wanting to hurt a lady’s feelings, “I mean, I wouldn’t want to interrupt your sleep schedule, especially in such stressful times-”

Monica huffed. “You can’t be serious, I know a playboy like you would rather be with a beauty like me than Mr. Stick-in-the-mud there.”

It was getting more and more awkward to bring up the fact that he didn’t find Monica attractive. “Uh… I mean… He’s not a  _complete,_ uh…”

“Let me clarify a few things,” Felix interrupted.

Before Sylvain could fully process what was happening, Felix grabbed his face and mashed their lips together.

Sylvain’s brain went absolutely kaput, all he could process was the heat rising to his face and the unfortunately terrible job Felix was doing kissing him.

It wasn’t until he heard Monica’s undignified squeak of shock that he realized that there might be a logical reason for Felix to suddenly attempt to make out with him. Felix’s movement slowed and he started to pull back, but Sylvain realized that he hadn’t even responded at all to the kiss.

So he lifted his arms up, settling them around Felix as he pulled him in to deepen the kiss. With Sylvain properly responding, the experience was surprisingly enjoyable. It felt… different from his usual kisses, a little more nervous and a little more tender than he was accustomed to.

When they finally parted, Monica was staring with a gaping mouth. Felix, face red, glared at her. “Can’t you take a hint? Sylvain is  _mine,_ so back off.”

Monica didn’t even respond, just huffed and stomped away.

Once she was gone, Felix pulled Sylvain along deeper down the hallway.

For some reason Sylvain’s heart was pounding. Was that kiss really just some convoluted plan to throw Monica off? Felix seemed to be avoiding looking back, was he embarrassed about kissing his friend? Or…

Once they were in admin, Felix closed the door behind them. “What was that about?” Felix asked sharply.

“W-what was _that_ about?” Sylvain sputtered, brain scrambled by a revelation he was afraid to face, “I’m not the one who suddenly made out with you!”

“Not-” Felix looked away. “I mean, you made that idiotic face and then literally mouthed ‘help’ to me like you were in danger.”

Sylvain laughed, starting to recover his wits when faced with Felix’s familiar brand of criticism. “Aw, were you worried about me?”

He glared. “There’s a murderer loose on this ship, so I’ll admit,  _yes,_ I was a  _little worried_ when you panicked about going off alone with someone. Is she-?”

“No, she’s not the murderer.”

That made Felix’s brows furrow. “…Then why?”

“I just…” Sylvain felt a little guilt, knowing the scope of what Felix worried about was much more severe than the actual threat. “…Felt rude rejecting her.”

Felix took a very deep breath.

“So, uh, thanks?” Syvain ventured.

“I thought you were in _danger_ and it turns out you were just being immature, as usual.”

“So that was just a… just a ‘anything-to-get-me-out-of-danger’ kind of kiss?” Sylvain asked, feeling more hesitant than he sounded.

Felix paused a moment before changing the subject. “Swipe your card, Sylvain.”

  
  


* * *

  
  


The third body was found in the garden the next day.

**Notes for the Chapter:**

> sorry if you're not into Felix/Sylvain, but I find Sylvain most tolerable when he's falling in love with Felix 😅


	4. Gilbert

**Summary for the Chapter:**

> There is a revelation about the murderer, a plan by Lysithea, a command from Edelgard, and a group studying in the library....

**Notes for the Chapter:**

> Sorry if you're a big fan of Gilbert

“So you’re the gatekeeper in charge of guarding the control room?”

“Yes, it’d be a real pickle if anyone got in there who isn’t authorized, so I spend pretty much the whole day guarding it!”

Byleth wrote that down in their journal. Around them, others were listening intently to the testimony. The facts of the situation meant that there was a chance they would be able to figure out the murderer for certain this time. “And the entrance to the control room is right across the entrance to the greenhouse?”

“That’s right! I see everyone who goes in and out of the greenhouse.”

Byleth glanced around the room. “Can anyone confirm that the door this gatekeeper can see is the _only_ entrance to the greenhouse?”

Several people chimed in to agree.

Satisfied, Byleth continued. “So what did you see in the hours leading up to Gilbert’s murder?”

“Well, around 1500, I saw Ferdinand enter the greenhouse and leave a few minutes later with a flower. Several minutes later, Dorothea entered and left with a different flower.”

Byleth glanced around, and noted that Manuela had a flower tucked behind each ear. Rather than linger on that, though they focused on what was relevant to the investigation. “Ferdinand and Dorothea, was there anyone else in the greenhouse while you were there?”

They both shook their heads. “I would have noticed,” Dorothea added, “I searched carefully through the gardens for the perfect flower to gift… someone. I’m certain there was no one else in the greenhouse when I left.”

“Alright. Gatekeeper, continue where you left off.”

“Well, after that, there wasn’t anyone for awhile until about 1600, when Gilbert went into the greenhouse.”

Byleth felt so pleased that she _almost_ smiled. The setup was clear, whoever had entered between when Gilbert went into the greenhouse and the group who found the body was the murderer. “Then who next went in after Gilbert?”

“Why, that group who found the body-- Ashe, Dedue, and Leonie. They all waved real friendly when they passed me.”

Byleth frowned.

“That doesn’t make sense!” Leonie declared, “The three of us went in together, I can testify that none of us murdered him! And I _never_ would have wanted Jeralt to die, _never,_ I swear-”

“It’s alright, Leonie,” Alois told her, “No one’s accusing you.”

“Yet,” Hubert added.

“But how could Gilbert have been murdered if no one entered the greenhouse?” Lysithea ventured.

The conference room began to grow loud as people spoke their thoughts aloud, and frustrations began to bubble. It was starting to get ugly, Byleth needed to put a stop to it before they made a rash vote and potentially killed someone innocent.

“Are we _certain_ that door is the only way to get into the greenhouse?” Byleth challenged, speaking over the din.

The others quieted once Byleth spoke, but Ashe spoke up, “Yes, there are no other doors.”

“It doesn’t have to be a door, think outside the box. Is there _any_ other way to get in there?”

Dedue spoke up. “There’s ventilation shafts.”

Leonie shook her head. “Those aren’t big enough for a person to fit through.”

“Unless the murderer isn’t human in the first place,” Claude suggested.

Everyone looked at him. Petra tilted her head, concerned. “Not… human?”

“I’m just saying,” Claude said with a shrug, “Shapeshifting aliens exist. I bet some of them have forms that could wriggle through a vent, in addition to forms that would make them look human.”

“But that’s-” Ingrid’s eyebrows were raised high as she spoke, “Are you saying someone here is… an impostor?”

“I’m saying that’s the most logical explanation for this.”

Byleth took a deep breath. This murder mystery got a whole lot harder.

  
  


* * *

  
  


Lysithea followed Manuela out of the conference room, into the medbay.

Not just the two of them, of course. Trios were the safest configuration at the moment, so Lysithea convinced Byleth to come along as well. Especially considering how out-of-the-way the medbay was, tucked into the end of a long hallway where almost no one went unless they were injured or had business with Manuela. The lack of varied company might have been why Manuela felt comfortable with having the room a mess, folders and various instruments scattered about the room without any apparent organizational system.

“I have a thought,” Lysithea told them once the medbay doors were closed, “One that could help the investigation.”

Both Byleth and Manuela stood a bit straighter, interested.

“Manuela, isn’t there a scanner here that can do a full-body diagnostic?”

Manuela grimaced. “Well…”

“As I recall, everyone was required to get a medscan during this trip, myself included.”

“That is, uh, _technically_ what’s supposed to happen…”

Byleth cut in, “Would a shapeshifter be caught by the medscan?”

Lysithea nodded. “It certainly identified _me.”_

Byleth’s gaze sharpened, and their hand moved to their belt, palming the hilt of their laser sword.

“Calm down, Byleth,” Manuela interrupted while rubbing her temple, “She’s not a shapeshifting alien.”

They still seemed suspicious, eyes narrowed.

“This is private information,” Lysithea told her, “But since it’s relevant for the investigation, I’ll tell you: I’m half-alien.”

Byleth’s eyes widened, then she glanced at Manuela.

“I noticed near the beginning of our voyage,” Manuela told her, “She was one of the first people I put through the medscan, and I noticed some significant abnormalities. She explained her heritage, I investigated, and I can assure you her species does not pose any danger.”

“…So no shapeshifting?” Byleth questioned.

Manuela shook her head. “For one thing, Lysithea is only half alien, and even full-blooded members of that species don’t have shapeshifting capabilities, they’re more specialized for cave and sub-surface survival because that’s their native environment. To be honest, it’s more to her detriment, since the lifespan of that species is a lot shorter than-”

Lysithea felt her face redden at the unnecessary information, so she interrupted, “To make a long story short: I’m evidence that the medscan will be able to identify aliens on the ship.”

That seemed to improve Byleth’s mood, and they looked at Manuela with hopeful eyes.

Manuela sighed, weary. “Unfortunately, the medscan broke about half-way through our voyage, so we can’t use it willy-nilly.”

Both Byleth and Lysithea frowned at that. “How did it break?” Lysithea asked, “Surely one of our mechanics could repair it.”

“I won’t get into the details of what exactly spilled onto the console and made everything fritz out, but I can tell you that it’s a proprietary device, and cannot be repaired by a third party.”

“This is an emergency situation, even if it voids the warranty I think it’s worth trying to repair it.”

Manuela shook her head. “It’s not just about warranty, there’s about a dozen safeguards in place, including explosives if you try to open the wrong panel without the correct proprietary tools.”

Byleth hummed, putting a hand on their chin. “So we can’t use that?”

Lysithea jerked up, as though realizing something. “What about the medical records? Even if you can’t scan people right now, you were supposed to scan everyone in the past, right?”

Manuela glanced around and wrung her hands together. “Yes I was… _supposed_ to scan everyone...”

Byleth narrowed her eyes.

“I mean, I just get so busy,” Manuela defended herself, “And I did scan _some_ people. But if people said they were also busy, I wasn’t always super prompt in rescheduling… the medscan can take several hours, you know, so there are some folks who may have slipped through the cracks.”

Although the situation was not as _easy_ as Lysithea was expecting, that didn’t mean they couldn’t salvage something out of it. “The records can still help us narrow down suspects. A shapeshifting alien would probably have avoided the medscan, so if you find out who _didn’t_ do the medscan, that’ll be helpful.”

The plan made the corners of Byleth’s lips turn up, into something almost resembling a smile. “Where are the medscan records?” They asked.

Manuela froze, eyes darting around the room. “Uh…”

There were stacks of folders and cabinets, papers sticking out of shoddily put together cardboard boxes with outdated labels, and no obvious system of storage.

Lysithea tried to be optimistic. “…They’re digitally stored, right?”

“In the medscanner itself, yes,” Manuela told her, “Which is broken. It also always gives a printout when it finishes a scan though, so I can check those assuming I can… find them.”

Byleth looked similar to how Lysithea felt: Not too confident in Manuela’s ability to sort through the mess.

Eventually, Byleth decided something. “You collect as many records as you can. In the meantime, we’ll continue our efforts to catch the murderer. Once you think you’ve collected enough, bring them to me so we can narrow our suspect list.”

Manuela smiled, though it didn’t reach her eyes. “Of course! I’ll do my best…”

* * *

As usual, Hubert walked Edelgard to her pod before going to his own.

“Step in for a moment,” Edelgard told him, interrupting their usual routine.

As always, though, Hubert did as she asked. The pod was small, but there was room enough for the two of them to sit comfortably. Edelgard had been thinking the whole way to the pods since the meeting.

Everyone knew that there was an impostor on the ship, and that the murderer was the impostor.

“Hubert, you need to keep your distance from me from now on.”

He did not make any expression, and Edelgard appreciated that. She wouldn’t know how to handle it if he were to cry or act hurt about a necessity like this. Instead, he asked a single word: “Why?”

She went through a speech she had already practiced in her head. “So far, we’ve almost always served as each other’s testimonies, since we spend so much time together. Although that’s helped us avoid suspicion, I’m afraid with the latest clue there’s a chance I will be… caught.”

Hubert crossed his arms. Still listening.

“And if I’m caught, they will notice that you’ve been providing alibis for me. They will have no choice but to assume that you were in on the murders, and deliberately impeding the investigation to assist me.”

He maintained his steely expression.

“I can’t change what I am, but Hubert… You’re _human,”_ Edelgard continued, resolutely maintaining a steady voice, “You don’t have to go down this path. If we keep our distance, we can establish reasonable doubt so it will be believable when you say you had no idea.”

Edelgard knew this was the only way. At this rate, with the investigation becoming more urgent with each new body, her end was inevitable. The best she could do was minimize the casualties. This was her path to walk, alone. To ask Hubert to follow her into an execution by airlock would be selfish and cruel beyond words.

“This may be my final request to you: Distance yourself from me.”

Hubert’s gaze was sharp as steel, and unyielding as iron. “No.”

And as simply as that, Edelgard knew she could not walk the path alone.

  
  


* * *

  
  


Linhardt pulled out another book.

Beside him, Hanneman groaned over a book as well.

“These- these are so outdated,” Hanneman said, “There’s no info tablets?”

Tomas, scanning the shelves for other relevant works to add to the stack, shook his head. “I did a search on the info tablet we have, but it didn’t have any information on shapeshifting aliens.”

Linhardt was also getting frustrated. Although he loved old-fashioned print books, and one of the things he admired most about the Garreg Mach Enterprise was their early-millenium style library with physical books, he couldn’t help but think a couple of well-stocked info tablets would have been much easier to search through.

“This is hopeless,” He bemoaned, resting his forehead in the tome he had flipped through, “I need a nap.”

Ignoring his complaints, Tomas dropped another book onto the table.

Linhardt read the cover, _The Complete Encyclopedic Guide._ “That’s a huge encyclopedia,” He commented, a little surprised that someone as old and frail-looking as Tomas had been able to bring it over.

Tomas chuckled. “Don’t be silly, that’s just the encyclopedic _index._ We can grab the actual encyclopedias once we find the sections we’ll want to examine.”

“I wish we were in range of a digital exchange library,” Linhardt complained, “Hanneman, didn’t you used to work for one?”

Hanneman paused, chewing over some thoughts before he responded, “…Now that you mention it, I think I may have an info tablet in my study that could help.”

Linhardt perked up. “Really?”

“Yes, a colleague of mine lent me an info tablet on unusual and dangerous organisms. I forgot to return it, but I vaguely recall reading _something_ about a rare species that could shapeshift…” Hanneman hummed, thinking hard, “I think it started with… A ‘d’? no, a ‘t’. Twills… Tinned… Twis-”

“Why don’t you go find the tablet?” Tomas suggested.

Hanneman stood up. “You make a good point, dear friend! I’ll be right back after I fetch the tablet from my study.”

He left the room, steps energetic but not breaking into anything as intense as a run. Tomas watched him leave with a small smile on his face.

“You think it’ll actually help?” Linhardt asked him.

Tomas was still smiling. “I think he’s on the right track.”

Linhardt sure hoped so. It was stressful to know anyone on the ship could be a murderer, it would be nice to at least know the species and the capabilities of the impostor.

“Oh I just thought of another book,” Tomas spoke aloud, “I’ll return shortly, but I think it’s buried somewhere in the back of this library.”

Linhardt waved him away. “Go ahead, I’m just gonna look through this book a little longer…”

Once Tomas was out of sight, somewhere in the depths of the shelves, Linhardt rested his face on the book again.

He’d just take a quick little nap…

  
  


* * *

  
  


When he woke up, Tomas was gently turning pages next to him, his nose buried in one of the encyclopedias.

Linhardt rubbed at his eyes. “Did Hanneman find that tablet?”

Tomas almost jumped at Linhardt’s voice, startled. He must have been deeply absorbed in his reading. “Now that you mention it, he’s been gone quite awhile…”

Linhardt glanced at a clock across the library. When he saw that it had been almost an hour since he fell asleep, there a tiny worry wiggled in his gut.

Tomas smiled kindly at him. “He probably got distracted, there’s a _lot_ to read in his study.”

“Yeah,” Linhardt took the comfort gladly, “We should probably go check on him and see if he’s found anything.”

Gingerly, Tomas stood up and grabbed his cane.

Linhardt led the way down the winding halls of the Garreg Mach Enterprise. He had only visited Hanneman’s study once, when Hanneman had lent him a rare text from his private collection, but he still remembered the way.

Once he reached the familiar door, Tomas close behind, he knocked. “Hanneman? You in there?”

There was no response.

That worry returned, ugly thoughts causing his stomach to turn.

Tomas knocked as well. “Hanneman, old friend?”

When that still elicited no reaction, Linhardt declared, “We’re coming in.”

He opened the door, and his fears were realized.

The study was a mess. Not the kind of mess that came from fervent research, passion overriding organization as curiosity led Hanneman down a dozen tracks, but the kind of mess that came from someone deliberately trashing a room, including destroying every tablet they could get their hands on.

And in the center, Hanneman’s body laid face-down, blood seeping out of his back.

**Notes for the Chapter:**

> Who is the best Fire Emblem: Three Houses character? Well that's an easy question, _obviously_ it's Gatekeeper.


	5. Hanneman

**Summary for the Chapter:**

> The second conference of the day, Marianne makes a confession, and uh oh O2 levels are low...

Byleth looked slowly around the room. After Linhardt and Tomas reported Hanneman’s body, there was another emergency conference. As much as Byleth hated another person dying, they couldn’t deny that this was valuable intel. This time, there was only a span of about an hour the murder could have happened, and almost everyone had been traveling in groups.

Most people had people corroborating their alibis this time, like Linhardt and Tomas who had been together in the library the whole hour Hanneman had gone missing. Although Byleth did not fully trust groups of two, accepting that there could be people who would vouch for each other as a matter of loyalty or bribery, they had to start somewhere with their suspicions.

For now, there were only three people who had no one to vouch for them. All three of them claimed to have been in their room the entire hour Hanneman could have been killed.

Bernadetta, Jeritza, and Marianne.

“Did anyone see any of those three during the hour?” Byleth asked the room.

Nobody volunteered information.

Bernadetta was curled up in a corner of the room, clearly uncomfortable with the attention on her. Edelgard and Hubert stood near her, almost protectively, shielding her from too many stares. Jeritza stood tall and seemingly unbothered by those suspicious of him. Marianne kept her head down, staring at the ground with an exhausted expression. Her hands were clasped, as though praying for something.

There was no definitive proof.

“I’ve been told you three tend to spend time alone, but as these are dangerous times I’m going to ask others to stick to them. Remember, groups of three are safest, three or larger should be the goal.”

With that, Byleth dismissed the conference.  
  


* * *

Hilda whined, “Marianne, you  _can’t_ go right back to your room, didn’t you hear what Byleth said?”

Marianne was struggling to pull her door shut, but despite her efforts Hilda was tugging the door as well, and despite Hilda’s small frame she packed enough muscle to keep the door open.

Claude came up behind Hilda, peering around her to see Marianne’s stubborn form. “Marianne, we’re supposed to stick together,” He reminded her.

“You guys shouldn’t,” Marianne mumbled.

“But if someone gets murdered, we need to be able to vouch for you!” Hilda exclaimed.

“Don’t bother,” Marianne insisted.

“Come on-”

“Please _don’t!”_ Marianne got as close to a shout as Hilda had ever heard, and tried to slam the door shut.

Fortunately, Claude grabbed the doorframe along with Hilda, making it impossible to close. All he r shouting did was attract some more crewmembers of the Golden Deer, who started to gather around.

Claude frowned. “Marianne, if you keep avoiding us like this, people will think you’re the impostor.”

Marianne kept her head down. “Maybe I am.”

Those around stiffened at the half-hearted admission. Raphael, a little distance behind Claude, tilted his head. “Uh, what’s that supposed to mean? Wouldn’t you know if you’ve been killing people?”

Marianne burst into tears.

Hilda took action immediately, grabbing Marianne’s shoulder and pulling her out of the room. It seemed the confession had taken enough out of her that she didn’t resist Hilda pulling her close. “Hey, hey,” She tried to keep her voice light as she hugged her, “Let’s not jump to conclusions.”

“What if I’m the murderer?” Marianne sobbed, “You’re all in danger, you should leave me alone.”

“Marianne!” Leonie exclaimed, “You’re not making any sense, but we would never abandon you.”

Marianne shook her head. “I’m… You can’t trust me.”

Hilda pulled her further out of her room, so she could see just how many people were concerned about her.  B y now everyone in the Golden Deer had come to check out the commotion, and all were confused about what was going on.  Marianne normally kept  quiet , so seeing her break down  put everyone on edge. Hilda knew that Marianne was too clumsy to ever commit a murder, though, so she had to get to the bottom of why Marianne was speaking so strangely.  “Let’s sit down and talk this out, okay? ”

Marianne surrendered to Hilda’s guidance, taking a seat in the common room as others gathered and took their own seats.

“I need to confess,” Marianne sobbed, “Call a conference, talk to Byleth\- you need to vote me off.”

Everyone glanced around at each other, disturbed, but Hilda was not convinced that Marianne was the killer. She was prone to overthinking and making assumptions, s o Hilda needed to investigate more before bringing the rest of the crew in on it.

Claude recovered first to respond, “No way!  I f you actually did kill them… Talk to us, I’m sure you had good reason, and we can help you escape-”

“Claude!” Leonie and Hilda both chastised him at the same time.

He raised his hands in surrender. “Hey! I’m just trying to comfort her in case she  _ is  _ the killer! _ ” _

“I really can’t imagine that’s actually the case,” Ignatz muttered.

“Marianne, why do you think you might be the killer?” Hilda put them back on the right track.

Marianne’s shoulder shook. “I- My family… I have cursed blood running through my veins.”

Everyone waited quietly, she seemed delicate enough at this moment that rushing her would just lead to a larger breakdown.

“The truth is, a long time ago, my family was part of a biological experiment- something highly experimental, that was supposed to make them stronger.”

Hilda hadn’t heard of this before. Marianne was usually rather quiet about her family; Hilda knew that she had been adopted by a distant relative after her parents died… had her parents’ deaths been related to this?

“It didn’t seem to work, so they went and had a family. But after some years, there were rumors of a beast roaming their planet at night, and they- they-…” Marianne’s face was pale.

Hilda held her hand. “It’s okay, take a deep breath if you need it.”

Marianne must have forgotten to breath, because the breath she took at Hilda’s urging was large and deep. “The monster killed people. It wasn’t until after  my ancestor disappeared and the beast was seen all the time that people started making the connection.”

“The beast… was your ancestor?” Ignatz asked.

She nodded. “And since then, occasionally in my family, someone will start transforming in the night, becoming a murderous beast, only to wake up the next day with no memory of what they did. This curse gets progressively worse, until they turn into the beast permanently.”

Claude made the connection. “So you think this curse has been passed onto you, and that you’re unknowingly killing people?”

Marianne lowered her head. “I’m sorry, I’m so sorry, I should have confessed earlier, but this is all my fault-”

Hilda couldn’t stand for this. “You don’t need to apologize, Marianne! We don’t even know if the curse is _actually_ affecting you, nobody has seen sign of a beast have they?”

She glanced around and everyone shook their head. Raphael laughed. “If I saw a beast roaming these halls, I would have wrestled it to the ground!”

Lysithea stepped forward. “Marianne, just because you have something non-human running through your veins… It doesn’t mean you’re evil or undeserving of help.”

Marianne shook her head. “But I’m  _cursed,_ it might very well be me killing everyone, and I could kill you guys too-”

“Let’s stop and think about this logically,” Hilda interrupted before Marianne could go too deep into despair, “You’d have to be asleep during these murders to have committed them, right?”

Marianne bit her lip. “I… suppose, yes,  for now. ”

“But only Anna and Jeritza were killed at night, the rest were killed during the day.”

“After the conference this morning, I went and took a nap until the next conference, where Hanneman’s murder was announced.”

Hilda frowned. “Still, at the  _very_ least, you could not have killed Gilbert.”

Lorenz added, “And surely if you turned into a beast, someone would have noticed you roaming the halls during the day.”

Marianne didn’t seem fully convinced, but at least she was mulling it over, brows furrowed as she processed the information.

“I think we’re overlooking an easy solution to this,” Hilda decided, “Group sleepover!”

Everyone was surprised at that idea, although Hilda thought it made a lot of sense. “Uh…” Lorenz raised an eyebrow, “Like… out here in the common room?”

“Yes!” Hilda grabbed both of Marianne’s hands, trying to transfer some comfort through their touch, “We can watch over you all night, Marianne, and we’ll make _sure_ that you’re not turning into some beast.” Hilda looked around the room. “It’s the least we can do for our Marianne, right?”

People nodded, amendable to the suggestion. Claude said, “And along with that, Marianne, your situation means you should  _always_ be with people instead of isolating yourself, so we can keep an eye on you and reassure you that you’re not the murderer.”

Marianne started crying again.

“Oh no,” Hilda hugged her again, letting her cry on her shoulder, “Too much?”

“You guys are too good for me,” Marianne eventually choked out.

Claude laughed. “We love you too, Marianne.”

Hilda was about to add in some comforting words of her own, but a loud alarm blared and startled everyone. The lights along the walls blinked red, and an automated voice spoke over the intercom:

“ _Oxygen depletion detected. Please repair at both oxygen stations.”_

  
  


* * *

  
  


Hubert and Edelgard ran as the alarm blared above them.

“ _Oxygen depleting. Full depletion in ninety seconds. Please repair at both oxygen stations.”_

They were close to one of the stations, and Edelgard turned in its direction.

Hubert glanced the opposite direction, making desperate plans in his head. “You go to the nearby one, I’ll head across the station to admin…”

“You’ll never make it in time,” Edelgard told him, “Follow me. I have a plan.”

She had a point. The many hallways he would have to go down made a convoluted route that he, with rather low stamina, would be unlikely to get through in under ninety seconds. Though Hubert did not know what her plan would be, he was not in the habit of doubting Edelgard, so he followed as she sprinted down the halls to the door of the O2 room.

There was no one else inside, which made sense considering it was tucked away in a corner near the Black Eagles House. In theory, though, there should be plenty of people flooding in to input the code to repair the oxygen system. If fate smiled on them, others would also be flooding admin to input the code in the panel there.

Unfortunately, neither Hubert nor Edelgard trusted fate.

As Hubert closed the door to O2, Edelgard pried open a vent.

“What are you _doing?”_ Hubert hissed.

“You input the code here,” Edelgard told him, “This vent can get me to admin in seconds, I’ll input the code there-”

“You could be caught,” He told her sharply, “It’s too risky, and not worth it considering you’ll survive even if oxygen gets depleted.”

“ _You_ won’t,” Edelgard countered.

She was already transforming, turning slimy and malleable enough to slip through the vents, but Hubert wasn’t ready to let her go that easily. “There will almost definitely be people going into admin…”

“ _Full depletion in sixty seconds.”_

“We don’t have time to argue,” Edelgard spoke, her mouth floating around the gooey shape she was becoming, “Look, I’ll wait beneath the vent, and only come out if I don’t see anyone else in admin.”

He still didn’t like it, but he supposed that was the safest he was going to get her. “Alright.”

She disappeared quickly, the vent rattling behind her.

As he began typing the input code into the panel of the room, the door to O2 slammed open.

Ferdinand rushed in, Petra close behind.

“Done?” Petra asked, eyes wide and concerned.

Hubert nodded as his finger finished the code. “On this end, at least. Hopefully there’s someone in admin…”

“ _Oxygen restored. Recalibrating…”_

The three of them breathed a sigh of relief.

Ferdinand glanced around. “…No Edelgard with you?”

Hubert resisted the urge to glance at the loose vent. “She thought it prudent to check the admin panel while I did this one.”

He laughed. “Not even Edelgard could make it there in time.”

“It is better to try than not at all,” Petra defended her.

Ferdinand didn’t acknowledge the comment, lost in his usual delusions. “Now me on the other hand… I was one of the fastest sprinters in the Aegir System olympia tournaments as a teenager…”

Although there were times Hubert would allow Ferdinand to chatter on, letting his ridiculous boasts and ideals wash over him like white noise, he was hyper-aware of Edelgard likely waiting in the vents. “You two should get to your tasks.”

Ferdinand huffed at being interrupted, but made his way to the exit. “You can’t stop thinking of work for two seconds, can you?”

Although Petra also approached the exit, she turned back and noted Hubert remaining in place. “Not coming with us?” She asked.

He shook his head, maintaining a poker face. “I will clean the O2 filter. In case that’s what caused it to malfunction.”

Petra narrowed her eyes. Hubert suppressed every nervous tic he was aware of himself having. Petra sometimes struggled with language due to the nature of the translators everyone on the ship wore. Despite many translators being purported as ‘universal’, in truth there were many smaller systems’ languages that were unsupported or shoddily added to the software, and Petra’s home system of Brigid was one of them. Though she had been slowly modding the translator for more accurate translations, she had also relied on nonverbal cues to guide her through much of her communication with her crewmates. She had grown sharp when it came to body language and facial tells.

In other words, if there was anyone who could realize there was something suspicious about Hubert’s behavior, it would be Petra.

Fortunately, despite a raised eyebrow, she did not press him on the matter. “I must do wires,” She said as she left with Ferdinand.

As soon as the door closed. He breathed a sigh of relief.

“They’re gone,” He said to the empty room, “It’s safe.”

The vent wriggled, and a red mass crawled out.

Slowly, the mass began reshaping, creating something almost like an arm, another part almost like a face-

The door opened.

Flayn entered, eyes scanning the room without enough time for Edelgard to go back into hiding. Flayn froze when she saw the blob snapping into a humanoid form.

Her eyes widened, and she opened her mouth to scream-

**Notes for the Chapter:**

> Sorry for the cliffhanger I'll update in the next few days.
> 
> My biggest ship is Marianne/Support.


	6. Flayn

**Summary for the Chapter:**

> Jeritza confronts Hubert, there's an emergency meeting, and Manuela has a _very valuable_ clue.

Jertiza walked briskly to the medbay.

Despite Byleth’s demand that he move in groups with others, he felt it inconvenient. He was just going to swing by medbay and get some medicine for his headache. Despite Manuela’s disorganization, he could at least find those without her presence.

Yes, he deliberately went to medbay when he knew she would be gone. Despite her irresponsible lifestyle, she kept a fairly consistent lunch and dinner schedule, so if he didn’t want to interact with the flirtatious woman he liked to go to medbay during that time.

When he opened the door, he saw he was not the only one aware of her absentee times.

Hubert froze at the interruption, an amber bottle his hand. Hubert quickly palmed the container, hiding it in his pockets as though Jeritza would let it go.

Jeritza wanted to let it go.

But those amber bottles were not the typical over-the-counter pills that crewmates could safely use. He glanced to Manuela’s locked medicine cabinet, where the more controlled drugs were stored, and saw it had been opened.

He wouldn’t be surprised if Manuela had forgotten to lock it, but if Hubert was trying to access something he could guarantee Hubert would have found a way to pick the lock regardless. 

Hubert saw Jeritza’s gaze flicker to that cabinet, and he slammed the door shut. “Manuela asked me to get her some materials,” He claimed.

Jeritza knew it was a lie. There was no obvious tell, but he knew Hubert lied as easily as he breathed.

He had known both Hubert and Edelgard long before joining the Garreg Mach Enterprise. Long ago, in the Adrestrian system, when the two were children. Though he had only spent a short time around them back then, he often found himself projecting the wide eyes and distrusting expressions of those children onto the two adults on this ship today.

Perhaps those memories of them, smaller and more vulnerable, was what made Jeritza hesitate to either let him go or call Manuela over to report Hubert.

“What did you take?” Jeritza asked.

Hubert’s gaze sharpened. Jeritza had seen that look before. In the Adrestrian system, Jeritza noted that Edelgard’s enemies would occasionally die  under mysterious circumstances. Though Jeritza had learned of her… secret, his vow to maintain secrecy had shielded him from any assassination attempts from them. On this ship, Jeritza generally kept a polite distance from those two.

He hoped the fact that he had not told a soul of Edelgard’s species, despite the current extenuating circumstances on the ship, would garner at least a little trust from the two of them. The fact was, Jeritza carried more than enough sins of his own to judge the things children did to survive.

“Just a little something to help Edelgard sleep at night,” Hubert told him.

“Sleep aids do not come in such bottles.”

Hubert’s lips pursed. “It’s none of your business.”

Jeritza saw the stress on Hubert’s face. He felt something in his gut, a gross discomfort at knowing someone who hadn’t been allowed a childhood was still struggling, and with something he couldn’t tell Jeritza.

Though Hubert made to escape, power-walking to the exit, Jertiza closed the door and blocked it with his body. Hubert may be capable of murder, but his methods were obtuse. Poisonings, engineered accidents, and surprise attacks were his wheelhouse. When it came to a direct confrontation, Jeritza could dance circles around Hubert in combat.

Hubert seemed to realize this as well, as he aborted his escape attempt and returned to negotiation. “There is a… situation that you need not concern yourself with.”

Jeritza remembered how Hubert and Edelgard had fought for their lives in the Adrestrian System, becoming an unstoppable duo that people feared and admired. Although their skills were admirable, they had no trust for others. Despite Jeritza briefly harboring them when they were injured, they strove to never require his assistance again.

Perhaps it was hypocritical for Jeritza to judge them for not relying on others, when he himself was a lone wolf… but he still saw those scared, injured children when he looked at them, and couldn’t bring himself to turn away from them, even today. “Just tell me,” Jeritza told him.

Hubert bristled, “It’s private.”

“I won’t tell Byleth.”

That made Hubert pause.

“Even if Edelgard is the killer-”

“ _Don’t_ say that,” Hubert hissed.

“-I won’t tell anyone.”

That made Hubert pause. “…You swear?”

“I swear on it. I haven’t told anyone about Edelgard so far, why should I start now?”

Hubert deliberated for a minute, face serious. Jeritza did not make any sudden moves, not wanting to startle him. 

Slowly, Hubert held out his hand, bottle label facing outwards. Jeritza squinted and stepped forward, reading the label.

“…That’s the kind of stuff that could kill someone,” He commented.

“ _Any_ drug can kill someone in excess,” Hubert informed him, “This drug, in the correct dosage, administered regularly, can maintain a coma indefinitely.”

“…”

“The coma is reversible with minimal side effects.”

“Surely Edelgard’s sleep schedule is not so wretched that she needs to be put in a coma.”

Hubert chuckled. “I’m sure by now you’ve gathered it’s not for Edelgard.”

Jeritza stayed silent, waiting for Hubert to explain more. He would not move from the door until he knew exactly what Hubert’s plan was.

“…Someone saw Edelgard shapeshifting,” He admitted, “We… we can’t risk someone accusing her. We need them out of the picture, at least until the ship reaches a planet and we can escape.”

Jeritza raised an eyebrow. “I was aware of Edelgard’s species, why have you not put me in a coma?”

Hubert glanced away before responding, “We…” Hubert’s voice grew quiet, “…Perhaps… trust you, for lack of a better word.”

Jeritza did not know how to respond to that. It felt hard to swallow all of a sudden. “Ah.”

Hubert coughed. “Anyways, I should go. Manuela’s dinner break shall be over in a few minutes.”

“Where are you keeping them?” Jeritza asked.

Hubert’s brow furrowed. “You don’t need to know that.”

“Put them in my pod.”

That stymied Hubert for a moment before he caught his bearings. “…Why would we do that?”

“The pods in the administration sector are larger than those in the Houses,” He justified.

“Why would _you_ offer this?” Hubert asked with narrowed eyes.

Jeritza wasn’t entirely sure himself. “…I suppose you two remind me of… little siblings.” He didn’t know how else to describe the feeling.

Hubert’s face twisted towards a slight disgust.

“…Please allow me to take on a little of the burden. I’m sure Edelgard is having a hard enough time hiding her species _without_ also hiding a whole person in her pod.”

Though Hubert still did not seem thrilled about the prospect, Jeritza was not moving from the medbay door until he responded. He let out a sigh, and said, “Fine.”

Somehow, it relieved Jeritza.

* * *

Despite the emergency meeting, Flayn did not turn up.

“I’m certain now, my d-” Seteth coughed. _“Dear_ sister, Flayn, has gone missing. She did not return to her pod last night, and though I searched all morning, I have been unable to locate her.”

“Perhaps she’s stretching her wings,” Claude commented idly, “Having such an overbearing older brother must be difficult.”

Seteth’s glare made Claude wince. “She would not ignore the emergency meeting alarm. Not unless she was _unable_ to.”

Annette tried to smile. “If we haven’t found a body, there’s a chance she’s still alive!”

“But why would the impostor change tactics _now?”_ Lysithea thought out loud.

Seteth took in a sharp breath, pinching his brow. Byleth sensed that perhaps it was getting difficult for him to continue leading the meeting, so they stood up. “It is imperative that everyone keep an eye out for Flayn. Let’s determine who last saw her, and where.”

“She was running towards O2 when the oxygen was depleting,” Dmitri testified.

Beside him, Dedue and Annette nodded. They must have been traveling together at the time.

“Ferdinand and I also saw her,” Petra cut in, “In the hallway, after the emergency was done.”

“She wasn’t running at that point,” Ferdinand added, “But she was heading the opposite direction of us. We offered to walk with her, but she said she was fine…” He frowned, “Maybe, if Petra and I had insisted on accompanying her…”

“We can’t change the past,” Byleth blew past the regrets, since those were not helpful for the investigation, “Did she say where she was going?”

“If she was running to O2 earlier, perhaps she went there to check in?” Ferdinand ventured, glancing at Hubert.

Hubert shook his head. “I spent half an hour in O2 after the emergency, cleaning out the filter, and she did not come in.”

“Alone?” Claude challenged with a raised eyebrow.

“If you’re wondering about me,” Edelgard recognized Claude’s implication, “I was not there for the emergency, but I joined Hubert afterwards. I did not see Flayn either.”

“Hmm.” Claude crossed his legs. “Kinda sus, if you ask me.”

Edelgard rolled her eyes. “Hubert and I are not attached at the hip.”

Byleth had to focus the conversation back to the facts. “Did anyone aside from Petra and Ferdinand see Flayn after the oxygen emergency?”

Nobody spoke up.

“In that case, we’ll investigate the area of the ship near O2 for now, and see if we can find…” Byleth avoided saying ‘body’ for Seteth’s sake. “…Any clues. Meeting dismissed.”

People filed out, chattering. Tensions were high, this was the first time they hadn’t found a body, and there was a strange mixture of hope that there had not  _ actually _ been a murder, and concern at the change in behavior from their impostor. What was their goal?

Beside Byleth, Seteth accepted a few words of support from some crewmates. Ingrid, Ashe, and Monica spoke gently to him.

“Byleth?” Manuela asked.

Byleth snapped their gaze to the doctor of the ship. “What is it?”

“I’m almost done collating the medscan records,” Manuela told her, “There was a lot more than I thought, I think we might be able to effectively narrow down who the impostor is.”

That gave Byleth reason to smile. “I’m glad to hear it.”

“Come with me, and I’ll show you what I have so far.”

Byleth shook their head. “I need to investigate the area where Flayn was last seen first. You finish finding those records, then I’ll meet you in medbay.”

Manuela pouted. “Well, alright. See you soon?”

Byleth nodded.

  
  


* * *

  
  


Manuela was  _ so close _ to finding out who the murderer was. There was a set of crewmates who had fully dodged Manuela’s medscans. Though it could be a coincidence, this would at least allow them to narrow down the list of suspects. Or even allow them to know who they could likely trust, which was fortunately a long list.

She smiled as she discovered another folder. When she opened it, she was thrilled to discover it contained medscan data for eight whole  crewmembers . Once she added it to the rest…

She had created a list of all the crewmates, and each time she found medscan records that confirmed they were human, she crossed them off the list. With this new influx of data, there were only a handful of suspicious crewmates left. They were…

The door to the medbay opened. “Manuela?”

Manuela froze. She knew that voice.

That voice had not been crossed off the list.

**Notes for the Chapter:**

> lol I just like Big Brother Jeritza vibes


	7. Manuela

**Summary for the Chapter:**

> After yet _another_ body is discovered, there's the second conference of the day. Desperate to find the murderer, the crew decides to search rooms...

“Two emergency meetings in one day?” Felix complained, “You know, _some_ of us have tasks to do.”

“Well some of us want to _not be murdered,”_ Sylvain shot back.

“We cannot ignore the fact that not only was Manuela killed, but the data she was collecting was trashed as well,” Byleth told the room, “Let’s establish who has an alibi for the time between our last conference and me finding her body in medbay.”

People went around the room, sharing their alibis and corroborating each other. Fortunately, with the three-person rule, even those who went searching for Flayn in niche areas were accounting for each other.

“Lorenz, and Lysithea, and I were all searching together on the opposite end of the ship,” Claude claimed, eliciting nods from his companions.

“Tomas, Linhardt and I were all in the library,” Monica claimed, Linhardt sleepily nodding beside her.

Hilda also spoke up, “Marianne was with me and Leonie this time, so she  _can’t_ be the murderer!”

Another person who had no alibi for the last murder was accounted for by Dorothea. “Petra and I were with Bernie the whole time.”

That triggered Byleth to look at the last person who had been unaccounted for last time: Jeritza.

Despite the pressure being put on him, he looked unperturbed. “I went to the kitchen for some food, then retired to my room after our previous conference.”

Claude narrowed his eyes. “You didn’t seem at all distressed by Flayn’s disappearance…”

“I have no attachment to her, why should I?”

“It’s _has_ to be him,” Monica declared, “That’s pretty damning evidence.”

“Now wait a minute,” Ignatz piped up, surprising considering how he usually tried to blend into the background, “That’s all circumstantial! We shouldn’t make rash decisions without hard evidence.”

Claude agreed. “We can’t dismiss the possibility of one or two people lying about alibis. Even if we hope the impostor has no collaborators, they could have bribed or blackmailed someone into testifying that they’re accounted for.”

“Was there anyone else without an alibi?” Edelgard intervened, “We should at least get a complete list of those before we start throwing around accusations.”

Although many people glared at Jeritza, minds already made up, Byleth continued collecting information from the rest of the crew.

Byleth eventually reached the last person in the room. “What about you, Seteth?”

He frowned. “In truth I also retired to my room. Flayn’s disappearance has made me…” He glanced away, “I’m not in a good state, I’d prefer if you all did not see me at my lowest.”

Hubert crossed his arms, giving Seteth an appraising look. “Awfully convenient that the one victim without a body happens to be your sister.”

Seteth glared at him with sunken eyes. “What is  _that_ supposed to mean?”

“It’s just convenient that no one would want to suspect the victim’s loved ones,” Hubert clarified, “And by having the loved one ‘disappear’ without a body, one could elicit sympathy and freedom of scrutiny without having to _actually_ murder their sister.”

Seteth stood up, slamming a fist against a table. “How  _dare_ you-”

Byleth put a hand on his shoulder, holding him back. “Stop.”

Right now the conference was just going in circles. They needed evidence.  _Hard_ evidence.

“Seteth, Jeritza, we are going to need to search both of your rooms,” Byleth decided.

“Fine,” Seteth conceded.

“Go ahead,” Jeritza agreed.

  
  


* * *

  
  


There was nothing of note in Seteth’s room. Like Jeralt, he seemed to have a penchant for writing, and Byleth idly wondered where Jeralt’s journal might be. It would make a good keepsake, but Byleth hadn’t paused in their investigation long enough to let sentimentality kick in.

“As you can see, there’s nothing suspicious in here,” Seteth declared.

There was a large group of crewmates that accompanied them to the room, and they all agreed there was no damning evidence. “Alright, let’s move on to Jeritza’s room then.”

  
  


* * *

  
  


…That was pretty damning evidence right there.

“Flayn!” Seteth cried out, dashing across the room to examine her body lying face-up, eyes-closed, on Jertiza’s cot.

Instantly, Dedue and Hilda grabbed Jeritza to prevent him making any attempts at escape or further murder. Fortunately, Jeritza seemed resigned to his fate, maintaining his stoic glare and not resisting as they marched him back to the conference room.

Though most crewmates followed, keeping weapons pointed at Jeritza in case he wanted to pull any funny business, a handful stayed with Byleth and Seteth to check on Flayn.

“She’s still breathing,” Seteth gasped out, a simultaneous expression of shock and relief on his face.

Mercedes bent down and examined the fluid being dripped into Flayn’s arm. Digging around the area revealed a dark bottle, whose contents Mercedes examined closely. Although Mercedes was not the official ship doctor, she had medical qualifications and was well-versed in drugs. “She’s being kept under with this, we should be able to stop the flow into her system with no side effects, though it may take a day or two for her to regain consciousness.”

Seteth gulped, breath heavy, and tears brimmed in his eyes. “I’m so glad.”

“Is there any immediate medical care we should give her?” Byleth asked.

Mercedes shook her head. “This drug has pretty minimal side effects, though being in a coma does require some care. It appears the drug solution is currently being dripped into her arm via the IV, which is also keeping her hydrated. We can bring her to medbay and replace that bag with a plain saline solution, and just make sure to keep an eye on her and have food for when she wakes up.”

“Can you two get her to medbay and hook her up while we deal with Jeritza?” Byleth asked.

Seteth nodded, but Mercedes seemed to hesitate. “I wouldn’t want to miss out on the vote.”

“Can you treat her in the conference room?”

Mercedes nodded.

  
  


* * *

  
  


It took a bit of time to roll out a cot and bring out a saline bag from medbay, but it seemed that almost everyone in the conference room was relieved to see Flayn alive.

However, the conference room was a bit of a bloodbath in its own way.

“Why would you do it?” Annette asked, tears flowing down her face, “Anna, Jeralt, Gilbert, Manuela… and even attempting to kill Flayn? Why?”

Apparently Jeritza was not open to discussion, as he kept his lips sealed.

“If everyone is here, I think we have a unanimous vote to throw him off this ship,” Ferdinand declared.

“W-wait,” Ignatz piped up, “We haven’t officially voted yet.”

It was messy, people shouting and crying at Jeritza as he stood, stock still while flanked by Dedue and Hilda.

“Everyone, quiet,” Byleth commanded the room, knowing that there needed to be some order to get anything done.

Fortunately, people were cooperative enough to comply, looking to Byleth as their detective.

They met Jeritza’s eyes. “Do you have a defense for yourself?”

He finally spoke. “No.”

“Do you have an explanation for why you murdered so many people?”

“…No.”

Byleth sighed. Though Jeritza’s case was likely hopeless with so much damning evidence, and they couldn’t imagine any defense that could absolve him, they would have at least like to know for what reason so many crewmates (and their father) lost their lives.

“You’re a _sick_ bastard,” Dorothea seethed.

Jeritza returned to maintaining his silence.

“If you will not defend yourself, we should put this up to a vote-”

“Wait!”

Everyone turned to Mercedes, who had just finished replacing Flayn’s IVs.

“I… I don’t believe Jeritza is the murderer,” She declared.

The room went into an uproar. It took a minute for Byleth to get crewmates quiet enough to ask Mercedes, “Why do you believe that?”

“I can’t deny that he had Flayn in his room, but I also can’t explain why he would kill everyone else but not her.” She glanced back at Flayn’s unconscious body. “There’s is no injury of any sort on her, and he was considerate enough to use a drug that is reversible. That kind of care is _not_ something I would associate with a murderer.”

Byleth looked at Jeritza. “Do you have any response to that?”

“I have nothing to say.”

Mercedes’s expression crumpled. “Any explanation would be good, we don’t have to vote you off if you give us at least  _some_ excuse-”

“I _said,”_ His voice grew sharp, “I have nothing to say.”

The room grew quiet, people unsure of how to react.

Ignatz spoke again. “I… I agree with Mercedes. And although he  _ did _ have Flayn in his room, he hasn’t actually confessed to any of the murders.”

“He also hasn’t said he _didn’t_ murder them, though,” Leonie cut in.

“ _And_ he doesn’t have an alibi for any of the other murders,” Linhardt added, “Even if he doesn’t directly confess, he’s basically the only person it could be.”

“I think it’s time for the vote,” Byleth decided, “If a majority agree, we will throw Jeritza off this ship. Please raise your hand if you believe Jeritza is the impostor.”

The room grew morose as people began raising their hands. Though there was some doubt cast in at the end, ultimately Jertiza had the odds stacked against him. Everyone had their hands raised except a select few.

Mercedes, Ignatz, and Raphael resolutely kept their hands down.

Despite them holding out, the majority was clear. “Take him to the airlock,” Byleth declared.


	8. Jeritza

**Summary for the Chapter:**

> Seteth ruminates, Flayn wakes up, and Jertiza has been ejected into dead space...

Seteth stayed by Flayn’s side as she slept, hoping for her to wake up any second. Mercedes and h e had moved Flayn into the medbay, where both of them remained while Jeritza was  suited up and  ejected.

Despite the shock of seeing Flayn unconscious, Seteth felt overwhelmingly relieved by her state, alive and unharmed.

He had even triple-checked with Mercedes, asking her to  examine F layn for any sort of injury, but Mercedes reassured him that aside from being made unconscious, nothing else had been done to her. Mercedes had her own hypotheses on the details. Since there was no blunt trauma on the head or anything, she suspected Flayn had initially been knocked out with chloroform or another short-term method before being hooked onto the coma-inducing drugs.

Whatever had exactly happened, Seteth was relieved to know that Flayn would be okay, and that she likely hadn’t struggled or suffered much at all before being put unconscious.

He was also  _ very _ relieved to know that the murderer had been ejected from the ship. He wasn’t sure exactly why Jeritza kept Flayn alive (Mercedes assured him that there was no evidence of Jeritza doing anything to her body  _ aside _ from inducing the coma ), but was counting his blessings that  Jeritza had mercy on her. Perhaps he couldn’t bring himself to kill children, which Flayn appeared to be.

Now they could have a peaceful journey. He was one of the few administrative personnel left, most of them having been murdered aside from himself and Alois. He felt a heavy burden on his shoulders. Although Byleth had led the investigation, it was ultimately his responsibility to lead the ship.

He ached to be at their destination, where Rhea was waiting for them. He wished Catherine and Shamir hadn’t gone ahead on their own ship. Though he wouldn’t deny them the opportunity for a ‘private journey’ as they described it (which he suspected to be akin to a honeymoon), he would have been much more confident on this ship with their support.

Would they have found the murderer earlier? Could they have stopped so many lives from being lost?

He decided not to linger on those thoughts. Regrets helped no one, he had to focus on the now.

“She probably won’t wake up until tomorrow at the earliest,” Mercedes informed him.

He stayed in his seat by her side. “I’ll stay here overnight.”

Mercedes smiled softly. “I will too.”

Seteth shook his head. “Don’t worry about it, the impostor is gone now-”

“Seteth,” Mercedes voice remained sweet, but there was a hint of something bitter underneath, “I said before that I didn’t believe Jeritza to be the murderer, and I still don’t. I believe there is still a murderer on this ship.”

“But Jeritza-”

“ _Especially_ with someone who was put unconscious for reasons we don’t know yet. If she has some knowledge on the true culprit, and Jeritza was hiding her for her protection-”

“I sincerely doubt-”

“I’m just saying,” Mercedes was still smiling, but her voice left no room for argument, “It wouldn’t be wise to leave an unconscious key witness in a room with only one person there to protect her.”

Seteth didn’t want to consider the possibility that the murderer was still at large. They whole crew had been on edge for so long, afraid of being murdered at any moment. Seteth thought himself saddled with the additional stress of having his daughter’s whereabouts and status kept up in air for over a day while an impostor was loose. Now that they had finally found someone with key evidence and no alibi for the murders, he wanted to finally relax into something resembling comfort.

Mercedes continued, a bit softer now, and not looking at Seteth, “…I don’t think it was right to kill Jeritza.”

She had always seemed gentle, perhaps she was so concerned because she felt uncomfortable with being complicit in someone’s death. “He was allowed to wear his spacesuit.”

“That’s as good as a death sentence in dead space,” She argued, “He’ll die in days, weeks at most. The chance of another ship passing through here is so small, he might as well be dead already. I wish…”

Seteth waited, but she didn’t go on. “…What do you wish?”

“I wished I could have saved him,” She admitted, “It’s not right. He didn’t admit to the murders… but he refused to defend himself.”

Seteth did not agree at all, but he didn’t think Mercedes would be comforted by those words. “You’re very kind.”

Mercedes frowned. “I don’t know if I would call it that.”

Their conversation faded into awkwardness, and Seteth refocused his attention on Flayn. She was still breathing, slow and steady. He put his fingers on the pulse of her wrist, and it thudded at about the same pace it had been since they found her.

“She’ll be alright,” Mercedes told him for the hundredth time.

He still appreciated those words. “Thank you.”

  
  


* * *

  
  


The world was hazy, muted. Flayn felt a deep sleep slip away as she slowly became aware of her limbs. She couldn’t see anything, but there was some noise filtering into her consciousness.

“…-she starting to-?”

“Give… some space, so-”

“Flayn? Can… me?”

She was relieved to hear her father’s voice. She had been panicked, hadn’t she? She was trying to recall why. What had she been doing before she fell asleep? Why did everything feel so weird? Why couldn’t she see anything?

Oh. Her eyes were closed.

Her eyes fluttered open, and she saw her father’s face looming over her, concern and hope etched in his features. “Father…” She whispered, throat feeling parched.

Seteth stiffened and glanced to the left. Was there someone else in the room?

“I’ll get her some water,” A familiar female voice said.

Though Flayn was not awake enough to identify her, the voice didn’t make her panic. Hadn’t there been a woman who had made her-?

“You’re safe,” Seteth reassured, “How are you feeling?”

“Tired,” Flayn spoke briefly.

Just as she thought about how thirsty she was, Mercedes (so  _ that’s _ who the voice was) passed a glass over to Seteth, who gingerly lifted Flayn’s head up and brought the edge of the glass to her lips.

She gulped the water thankfully. She also realized that perhaps she should try moving, and sat up properly.

“Don’t strain yourself,” Seteth said.

She shook her head. “I’m fine, I just-” She glanced around, “How long have I been out?”

“About two days,” Seteth told her, “You… you disappeared, but we found you yesterday. But don’t worry, we’ve ejected Jertiza, you’re safe now.”

Flayn’s brow furrowed. “Jeritza?” She asked, “What does he have to do with it?”

“You were found in his room,” Seteth informed her, “Wasn’t he the one who abducted you?”

“No, it was…” Flayn’s memories were coming back to her.

She had been going to the oxygen room. Even though the emergency had been dealt with, she though t changing out the filters would be prudent to prevent another disaster like that from happening again. But when she had opened the door, there had been a pulsing mass, an alien turning into one of her crewmates.

“It was Edelgard,” She finally remembered, “Edelgard is the impostor, and Hubert is in on it.”

* * *

Jeritza stared out into space. Endless, endless space.

The gigantic Garreg Mach Enterprise moved fast enough that it was out of his sight now. He was just trapped in zero gravity to slowly waste away and die.

He supposed he ought to regret his actions.

Edelgard and Hubert had voted for him. That was good, that would keep suspicion off of them.

Mercedes had not voted for him. He wished she had. He couldn’t get her face out of his head.

He wished they had just shot him, or cut his head off, or thrown him out the airlock unprotected.

Having him wear his spacesuit out here… it was just delaying the inevitable, letting him ruminate on everything he had done. If it were possible to get out  of  a spacesuit without another person’s help, he would have shed it already just to get his death over with.

Instead he was stuck, floating, alone. His oxygen tank would probably last him a day or two. After that, he could finally suffocate.

Jeritza was older than Edelgard and Hubert, and although those two had their own sins, he was certain his own were much greater. He wasn’t sure exactly  _ why _ those two killed all those people on the Garreg Mach Enterprise, but they were not the type to kill without reason. Otherwise they wouldn’t have gone to such efforts to keep Flayn alive.

If getting voted off could protect them for a little longer, he felt it was his duty. He had agreed to keep Flayn in his room, after all. Those two had finally relied on him again.

Perhaps he could meditate. Staring out into the endless abyss, perhaps he could rid his mind of all thoughts. There was nothing… nothing…

…Nothing but a speck of gray in the distance.

At first he thought it was an odd asteroid, but it was moving awfully fast for that. As it came closer, he saw it was shaped like a buggie. One of those little speedy ships, meant to hold no more than a few people, or even just a pilot and co-pilot. That’s what Jeralt and Byleth had come in on.

He realized that this buggie was about the same shape and type as the exact ship those two had docked onto the Garreg Mach Enterprise.

Well that was unusual.

What was even more unusual was that it was rapidly approaching him.

He stared, still not understanding until someone in a red spacesuit hopped out of a hatch, reaching out a hand to grab Jeritza and pull him in.

Edelgard.

He hadn’t even had time to process the thoughts before he was inside the little ship. Once the hatch was closed, Edelgard stripped herself of her helmet and pulled on Jeritza’s spacesuit, releasing him.

The ship was cramped, it was clearly designed for only two, and a glance towards the controls compartment showed that Hubert was in the co-pilot seat, continuing their journey.

Jeritza was still confused by what was going on. “What-?”

“We stole Byleth’s ship,” Edelgard explained, “It’ll be cramped, but we took some supplies from Garreg Mach to let us survive until we reach a planet or trading post.”

“But…” Jertiza frowned.

“Flayn was going to wake up and reveal Edelgard’s species,” Hubert spoke up, “So we decided to leave before they could vote us off too.”

“…And you came for me?”

Both of them avoided his eyes at the question, embarrassed. Still as awkward as ever.

Edelgard said, “You didn’t rat us out, even at the expense of your own life.”

Now Jeritza was getting embarrassed. They made him sound so noble. “I figured you guys had a reason for murdering those people. I figured if I was the scapegoat, you guys would be able to get away with it without killing anyone else.”

Both of them froze.

Jeritza tilted his head at their reaction. “…You guys  _ did _ have a good reason, right?”

“No,” Hubert said darkly, “We aren’t the murderers. Whoever killed all those people… They’re still on the Garreg Mach Enterprise.”

**Notes for the Chapter:**

> lolll sorry I ended up not killing off Jertiza... after giving him big bro vibes, I thought it would be too cruel to make him literally DIE for Edelgard and Hubert. Now that all three are off the ship, u can imagine a happy ending for them, but the rest of the crew are still unknowingly on a ship with the murderer...


	9. Jeralt's Journal

**Notes for the Chapter:**

> Haha the murderers are gone now.... right??

There had been some hiccups, but overall things were alright.

It was a shock to discover Edelgard and Hubert had escaped in the night, stealing Byleth’s ship, but it made sense after Flayn woke up and revealed that Edelgard had been the true impostor. Though it was unclear the exact role Jeritza played in their murders, he had to have at least been an accomplice to be hiding Flayn’s body, so Byleth tried not to have any regrets about ejecting him. 

Although they wished they could have ejected Edelgard and Hubert, perhaps it was for the best that they left on their own. Now there was no more fear on the ship, just relief that the murderers had removed themselves from their midst.

To celebrate, Byleth had finally allowed themself to relax, stretching out lazily on  t he i r cot.

The little pod that they had resided in along with Jeralt was originally Anna’s, but they still saw little sign’s of Jeralt in it.

His old coat, a box of his belongings, and the temporary cot that had been carted in to host him back when he had been alive…

Although Byleth was glad the murderers were gone, they were also angry that they had taken one of their last keepsakes from their father: Their ship.

Hopefully they would abandon the ship at the first trading post they came across. Finding that little buggie would be Byleth’s next quest, once the Garreg Mach Enterprise finally landed on its destination.

For now, though, all Byleth could do was bide their time. This large ship was not suited to chase down a speedy little ship like that, and Byleth couldn’t justify wasting the time and resources to chase it down anyway. It was better to get everyone to their destination, and to move on from there.

Still, now that the constant looming stress of murder was gone, Byleth found themselves thinking about Jeralt again.

The two of them were never the most affectionate pair… but there was no doubt that they were comfortable together. Byleth felt no longer whole, a hole left in their side where their father had always been.

It was difficult, but Byleth looked again at Jeralt’s old things. They hadn’t gone through them yet. It felt wrong.

And yet… Jeralt’s murderer was gone now. Justice had not been served, but Byleth could add that onto their list of things to do once off of this ship. They could chase the murderer to the edges of the universe, if they liked.

For now, though, all that was left to do was to go through what Jeralt had left and remember him.

They opened the box.

There was a ring. It was Byleth’s mother’s. Though Byleth couldn’t remember her, they still held the ring with a quiet awe. Jeralt would have wanted Byleth to keep it.

Beneath that were other knick-knacks, a little sculpture Byleth had attempted to make long ago at a craft market in some system Byleth could no longer remember the name of.

There was also Jeralt’s journal.

Byleth stared at it.

Slowly, gently, Byleth opened it, and read their father’s words.

* * *

Reading the journal was simultaneously healing and hurting. Those were their father’s words, his every thought. Byleth was in awe with how much he loved them, as well as his wife. They were saddened when they realized they were reaching the end of the journal, the last words Jeralt could share with them.

The last page. They took a deep breath.

_ Still collecting evidence. I spent the morning in the Black Eagle’s house, but no one had any good information. I might have a lead, though. _

Byleth frowned, continuing to read.

_ Monica asked if we could meet in electrical alone. She said she had something to say, but didn’t want anyone to overhear. I told her I’d meet her after lunch. Had a great meal, going there now. _

That was his last entry.

Byleth flipped the pages desperately, looking for anything else. There was nothing left but blank pages.

He had died before he could come back and report what Monica told him.

He had been murdered  _ in electrical. _

Byleth’s heart rate picked up. Had Monica admitted to being in electrical at all that day?

They flipped through their own journal, where they had been recording investigation notes. They searched through everything they had written on people’s alibis the conference after Jeralt’s murder.

_ Sylvain _ _ – Priming shields 1300-1600, with  _ _ Monica _

That didn’t make sense. If Monica was supposed to meet Jeralt, why would she have been with Sylvain?

And if Monica had lied… was Sylvain in on it too?

This warranted an emergency meeting.

* * *

“Why are we having another meeting?” Alois asked as the last few crewmates slipped into the conference room, “We caught the murderers, there’s nothing to worry about.”

“Wrong,” Byleth declared, holding up Jeralt’s journal, “I found this today: Jeralt’s journal. He wrote in it right before he went to electrical.”

Byleth’s eyes scanned the crowd, looking for Monica and Sylvain. Monica’s eyes widened at the journal, but Sylvain didn’t seem nervous.

“Before I continue,” Byleth settled her eyes on Sylvain, “Sylvain. After my father was murdered, the alibi you gave was that you were priming the shields with Monica.”

“Haha, yeah?” Sylvain responded.

“I want to be certain: Were you actually with Monica that entire time?”

The room grew quiet, everyone still confused as to why Byleth was bringing up an alibi from several murders ago.

Sylvain gulped. “The fact that you’re asking again kinda uh… Kinda makes me nervous, not gonna lie. You accusing me of something?”

“Your testimony is pivotal to making sense of some new evidence I’ve uncovered,” Byleth told him.

Sylvain glanced around the room. He made eye contact with Monica, but also with various others as well, before closing his eyes and taking a deep breath. “…I’ll be honest, no, I was  _ not _ with Monica.”

The room burst into shocked exclamations. Felix grabbed Sylvain’s arm as he spoke, “You  _ lied? _ How idiotic can you be?”

“But I _was_ priming the shields! I swear! Just… not with her.”

Byleth trained her eyes on Monica, who was sweating. “So, Monica? Where were you during Jeralt’s murder?”

Monica laughed, high pitched. “This is a misunderstanding. The truth is…” Her face was red. “I have a bit of a crush on Sylvain. I’m sorry if it sounds creepy, but I was… watching him. He didn’t see me, but nobody else saw me either. When I realized I didn’t have someone to confirm my innocence, I guess I selfishly clung onto him, since  _ technically _ I could vouch for him not being the murderer. He was nice enough to vouch for me too.”

Byleth almost jumped into the evidence, but Sylvain interrupted, “So you were watching me the whole time?”

“Yes,” Monica responded.

He crossed his arms. “So who was I with?”

Her eyes widened. “You-” She sputtered a moment, “I was just- I was just watching you-”

Sylvain turned to Byleth, a shit-eating grin on his face. “For various reasons, I did not want to reveal the identity of the woman I was with, but I will admit that I  _ was _ with a woman. If Monica cannot say who it was, that means she was not actually watching me.”

“I- I don’t know her name,” Monica choked out, “I don’t know everyone’s name-”

“She’s in this room,” Sylvain said with crossed arms, “Can you point her out?”

Monica glared at Sylvain. “Fine. Maybe I wasn’t watching Sylvain. I was on my own, but I was scared to not have an alibi, so I made stuff up. Happy?”

“Not quite,” Byleth opened up the journal, “My father’s last journal entry: ‘Monica asked if we could meet in electrical alone’.”

There were gasps throughout the room, and everyone’s gaze was trained on Monica, as though asking how she would get out of this one.

“W-what!?” She exclaimed, “I don’t know why Jeralt wrote that, but that didn’t happen!”

“I think it’s clear-” Byleth started.

“No!” Monica interrupted, “My alibi for that murder might not be corroborated, but when Hanneman was killed I was with Caspar and Petra the whole time, wasn’t I, guys?”

Although Caspar and Petra looked uncomfortable, they did admit it was true, “She was with us the  _ entire _ time from the conference up until the emergency conference to Hanneman’s murder.”

“So it _can’t_ be me,” Monica declared, desperate smile on her face, “I’m innocent.”

“Unless…” Claude stretched his arms out as he brought up another point, “There could be more than one impostor on this ship.”

The tension in the room skyrocketed. Everyone glanced suspiciously at each other.

“Think about it,” Claude ventured, “The _only_ person who never had an alibi for any murder was Jeritza. If there was only one murderer, he would be the only candidate. And yet, he, Edelgard, and Hubert all avoided killing Flayn. Like Mercedes said the other day, it doesn’t make sense to kill everyone else but not her.”

“Well if we’re going by that assumption, we should be suspecting the groups of two who often vouched for each other, like Edelgard and Hubert, who were _clearly_ the murderers,” Monica argued, “That’s why they ran!”

Lysithea thought out loud, “If we go by the assumption Monica is an impostor, but didn’t kill Hanneman, we can figure out who her accomplice is based on who didn’t have an alibi for his murder.”

Although Monica sputtered more excuses, Byleth was only growing more confident in her suspicion of Monica. Unfortunately, that also meant that there  _ had _ to be two impostors, and she needed to figure out who the other one was. She skipped around in her journal, checking what was written for alibis. “Bernadetta, Jeritza, and Marianne were alone during his murder.”

The remaining Black Eagles members gathered around Bernadetta, defending her, while the Golden Deer members gathered around Marianne in a similar fashion. Although it appeared neither house was willing to let their member be accused, Byleth had to move forward to solve this mystery.

“It has to be one of them.”

“It could have been Jeritza,” Dorothea insisted.

Mercedes said, “I thought we established that our assumptions about him were mistaken, and that he was  _ not _ actually a murderer.”

“We don’t know that for sure!”

The arguments continued, getting ugly.

Eventually, Lysithea brought up an important point, “Sylvain’s alibi was a lie, there could be someone who was lying this time too, or even just forgot something! We should double-check everyone’s alibis before we start throwing accusations around.”

That seemed logical. “Alright, let’s go over the facts…”

* * *

No matter how people were interrogated, it seemed Bernadetta and Marianne were the only suspects.

Tomas sighed. “I hate to say it… but Bernadetta is in the same house as Monica, is she not?”

Monica practically hissed. “Why are you acting like I’m definitely the murderer?”

Petra glared. “You are acting… How do you say it? Sus.”

“Perhaps she _is_ the only one,” Tomas ventured, “She could have persuaded Caspar and Petra to vouch for her with blackmail or threats.”

Petra frowned. “No, I vow she did not-”

“Ha!” Monica cackled, _“You’re_ suggesting I worked alone?”

Byleth frowned. What was Monica implying?

“We should eject her before she turns us all against each other,” Tomas spoke calmly.

“What? Afraid of me revealing something I shouldn’t?” Monica challenged.

Byleth wracked her brain. What was Tomas’s alibi? He had been in the library with Linhardt. Byleth glanced at Linhardt, who was yawning even in the midst of these accusations. “Linhardt… did you see Tomas the  _ entire _ time you were in the library.”

Linhardt started to nod, then paused. “Well… I may have taken a  _ little _ nap…”

“ _What,”_ Felix exclaimed, “Why didn’t you say that earlier?”

“Well to be fair I’m a light enough sleeper that if he had left the library, I would have heard the door open and close!” Linhardt defended, “So I know he didn’t leave the library! It didn’t seem relevant!”

Ashe spoke up. “…There’s a vent in the library.”

Everyone turned to Tomas, who had a tablet out. He pressed a button on the screen.

Then the lights went out.

* * *

There was chaos.

Felix grabbed at where he had last seen Sylvain. “Syl?”

Sylvain jumped at the touch. “You scared me-”

Once he figured out where he was, Felix pressed their backs together. “You watch my back, I’ll watch yours.”

“Uh, did you suddenly get night vision? Cause I did _not.”_

“Well this is better than just standing like sitting ducks-”

* * *

Dedue grabbed Dmitri and pushed through the alarmed crowd to get out of the room.

“Wh- Dedue, put me down!”

“We’re too vulnerable out here,” Dedue told him.

He heard a familiar squeak when he bumped into someone, and took the opportunity to grab him. “Ashe, you’re coming with us.”

“Dedue?” Ashe responded as he was pulled along.

He wasn’t sure how long the lights would be out, but if the impostors had night vision then they were doomed. Their best bet was to hide somewhere small and secure, with a single entrance they could guard.

* * *

Marianne stood stock still. If someone else was going to be murdered… it might as well be her.

Someone grabbed her. Yes, it was time for Marianne to finally free her house of her presence.

But instead of being stabbed, she was pulled close to a familiar shape. “Golden Deer!” Hilda announced, “Gather to the sound of my voice! We’ll survive if we stick together!”

Marianne flushed. Did she really deserve this care?

Hilda’s grip was tight. Marianne was somehow pulled closer, and she felt the press of other crewmates gathering close.

Hilda whispered, “I’m glad you’re okay. I was worried, since Tomas was behind you when the lights went out…”

Whether she deserved it or not… She was glad she wasn’t stabbed, for Hilda’s sake if nothing else.

* * *

Lorenz patted around the clump of Golden Deer students until he felt Raphael’s bulky muscles. “Raphael, where’s Ignatz?”

“I’m here,” Ignatz said, close to Raphael.

Lorenz reached out towards the voice, catching Ignatz’s familiar haircut and then sliding down to grab his hand. “You’re good at electrical, right?”

“Y-yes?” Ignatz flinched at a loud sound nearby.

They didn’t know what it was, but they didn’t have time to dally. “Then it’s your duty to get these lights back on.”

“W-what? In the middle of this?” Ignatz squeaked.

“We’ll go with you!” Raphael exclaimed, “Right, Lorenz?”

Lorenz nodded. “We need you, Ignatz. Otherwise we may perish.”

Ignatz took a deep breath. “Alright, for all my friends, I’ll get these lights back on! I can do it!”

* * *

Annette cried out as a pain pierced through her abdomen.

“Annie?” Mercedes cried out.

“T-they got me,” Annette gasped.

“They’re around here!” Mercedes cried out, even as her hands scrambled over Annette.

Annette winced as Mercedes patted the injury, and wheezed as Mercedes pressed against it to stop the bleeding. “M-Mercie-”

“I’m not letting you die on me, Annie. I still have more sweets I want to make for you.”

Annette laughed, then discovered that laughing hurt and stopped. With Mercedes’s determined voice, she could believe she wouldn’t die.

* * *

Sometimes, Lysithea hated her alien heritage. There were almost no advantages, and the massive disadvantage of a reduced lifespan.

Right now, though she never felt so blessed to have the little advantage of night vision.

She didn’t have a weapon, so she grabbed the stun gun Claude pretended he didn’t keep hidden in his pants all the time. “Hey, who-”

“Sorry, I’m borrowing this!” Lysithea explained, not slowing down at all.

Her legs were short, but clearly Tomas and Monica were not expecting anyone to be able to track them in the darkness, so they were not rushing. Tomas only took a few steps away from Annette after stabbing her, a crazed look on his face as his forehead grew, hair receded, and the sclera of his eyes went dark. Rather than use a weapon, his hands were bloodied by his attack, long claws extending from his fingers. He glanced around for his next victim, were they going for broke and trying to kill  _ everyone _ at once?

His gaze locked onto Linhardt.

_ Nope. _ No thank you.

She turned on the stun gun, and shoved it into Tomas’s side.

Although Lysithea wasn’t able to identify the species, even in his new form, electricity usually wrecked most life forms enough to disable or kill them. He certainly seemed to be affected, convulsing and collapsing onto the ground.

Lysithea looked around, she needed someone to hold him while she looked for Monica. Who…?

She grabbed Caspar’s hand and pressed it onto Tomas’s shoulder “This is Tomas! Secure him while I get Monica!” Lysithea shouted.

“Roger!” Caspar exclaimed, taking over, Lysithea was glad he was ready; she didn’t have time to explain any further. Several crewmates were nearby, and she heard Caspar calling for their assistance as she hurried to find the other impostor.

Where was Monica? Lysithea looked around desperately, but there were too many crowds. Monica’s red hair was distinct, but Lysithea’s night vision didn’t carry the same color acuity that day vision did.

She backed up, trying to get a larger view of the room. Where could she be? She had been near the Black Eagles at the beginning of the conference, but she wasn’t near anyone who had been there. Had she run out of the room completely?

She took another step back-

And a tentacle wrapped around her.

She screamed instinctively, terrified, then realized she still had the stun gun. She tried to turn it on whatever had grabbed her-

But unfortunately the creature had another tentacle, which slapped the weapon out of her hand.

A voice whispered into her ear, “Pathetic.”

_ Monica’s voice. _

A tentacle wrapped around Lysithea’s throat. Despite struggling, Lysithea couldn’t breathe.

Monica laughed. “We hoped to play with you vermin a little longer, but you’ve forced our hand. Now you will all-”

The lights came back on.

* * *

Byleth had definitely heard a scream to her left. Unfortunately, they couldn’t see anything. So they were stuck blindly stepping around, reaching a hand out to try and figure out what they were about to walk onto.

Their other hand was on her belt, resting on the hilt of their laser sword. Unfortunately, the light it produced was too little to light anything an inch beyond its blade, so Byleth kept it off. It was better not to draw the attention of the impostors,  _ wherever  _ they were.

They were certain they had heard Lysithea scream, did she need medical assistance? Byleth tried to listen closely, was there anything else they could hear?

Their blood froze as they recognized Monica’s voice, close to where the scream had been. “Now you will all-”

The lights came back on.

Wasting no time, Byleth turned on their laser sword and got into a fighting stance. Their eyes took a moment to adjust to the flood of light, but as soon as they did they registered someone with tentacles holding Lysithea in the air, choking her.

Instantly, Byleth struck, slicing the twist ed limb to force it to let go of Lysithea.

There was an anguished scream from the creature, which Byleth supposed must have been Monica. She looked much less human now, her hair faded to orange and strange markings on her face showing that her physical differences included more than just the addition of tentacles.

There was no vote, but there was no time to, since Monica was already preparing to kill another, claws going sharp to lunge at Byleth.

So they sliced Monica’s head off, hoping that would have some effect on the alien.

Fortunately it seemed to, and the body went limp. Beside her, Lysithea was gasping, catching her breath. She looked around desperately. “Tomas- there-” Lysithea said while pointing behind her.

Byleth rushed to the scene, where a pulsing mass was throwing off Caspar, Leonie, and Ingrid as they tried to contain it, barely dodging some sharp protrusions that resembled claws.

Done with mercy, Byleth took her laser sword and plunged it into the alien.

* * *

“I really hope this is the _last_ emergency meeting,” Ferdinand groaned.

Everyone had gathered again, though everyone stayed on the edges, uncomfortable with being close to the two alien bodies Byleth had pushed to the center of the room.

Not everyone was there, Annette had been carried to medbay and Mercedes was in there treating her with a few people. The wound looked bad, but Byleth felt confident that with Mercedes’s treatment she would pull through.

“I believe our fight is over,” Byleth said solemnly, “Annette was stabbed, but is being treated. Is everyone else okay?”

Though many had haunted expressions, there were nods all around.

* * *

Fortunately, it  _ was _ the last emergency meeting.

They arrived at their destination, most of them alive. Annette recovered with Mercedes by her side, and everyone gladly left the Garreg Mach Enterprise, full of memories of murder and betrayal. It was a relief to touch down on the ground, and to finally be free of the fear of murder hanging over their heads.

Byleth missed their father, but was glad they were able to avenge him.

Now the murder mystery was over.

And it was time to move on.

**Notes for the Chapter:**

> Thank you for reading this to the end! It was fun to play with the FE3H characters, and to build a little mystery (although if you're familiar with canon... you may have guessed a long while ago it was Monica and Tomas. I enjoyed putting a few hints and building it up tho). I really enjoy the large cast of Fire Emblem, which makes it hard to focus on just a few characters for me, so I thought it was very well suited for a large-group scenario like Among Us. I'm glad to have put this cross-over into existence.
> 
> Again, thanks for reading!

**Author's Note:**

> Check out [my tumblr.](https://jajalala.tumblr.com/)


End file.
